computer Education

Short Guide About Internet and its Components,Email

2014-07-29T23:04:00.003-07:00

About Internet

The Internet is a computer network made up of thousands of networks worldwide. No one knows exactly how many computers are connected to the Internet. It is certain, however, that these number in the millions.

No one is in charge of the Internet. There are organizations which develop technical aspects of this network and set standards for creating applications on it, but no governing body is in control. The Internet backbone, through which Internet traffic flows, is owned by private companies.

All computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, abbreviated to TCP/IP. Computers on the Internet use a client/server architecture. This means that the remote server machine provides files and services to the user's local client machine. Software can be installed on a client computer to take advantage of the latest access technology.

An Internet user has access to a wide variety of services: electronic mail, file transfer, vast information resources, interest group membership, interactive collaboration, multimedia displays, real-time broadcasting, shopping opportunities, breaking news, and much more.

The Internet consists primarily of a variety of access protocols. Many of these protocols feature programs that allow users to search for and retrieve material made available by the protocol.

COMPONENTS OF THE INTERNET

WORLD WIDE WEB

The World Wide Web (abbreviated as the Web or WWW) is a system of Internet servers that supports hypertext to access several Internet protocols on a single interface. Almost every protocol type available on the Internet is accessible on the Web. This includes e-mail, FTP, Telnet, and Usenet News. In addition to these, the World Wide Web has its own protocol: HyperText Transfer Protocol, or HTTP. These protocols will be explained later in this document.

The World Wide Web provides a single interface for accessing all these protocols. This creates a convenient and user-friendly environment. It is no longer necessary to be conversant in these protocols within separate, command-level environments. The Web gathers together these protocols into a single system. Because of this feature, and because of the Web's ability to work with multimedia and advanced programming languages, the Web is the fastest-growing component of the Internet.

The operation of the Web relies primarily on hypertext as its means of information retrieval. HyperText is a document containing words that connect to other documents. These words are called links and are selectable by the user. A single hypertext document can contain links to many documents. In the context of the Web, words or graphics may serve as links to other documents, images, video, and sound. Links may or may not follow a logical path, as each connection is programmed by the creator of the source document. Overall, the Web contains a complex virtual web of connections among a vast number of documents, graphics, videos, and sounds.

Producing hypertext for the Web is accomplished by creating documents with a language called HyperText Markup Language, or HTML. With HTML, tags are placed within the text to accomplish document formatting, visual features such as font size, italics and bold, and the creation of hypertext links. Graphics and multimedia may also be incorporated into an HTML document. HTML is an evolving language, with new tags being added as each upgrade of the language is developed and released. The World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee, coordinates the efforts of standardizing HTML. The W3C now calls the language XHTML and considers it to be an application of the XML language standard.

The World Wide Web consists of files, called pages or home pages, containing links to documents and resources throughout the Internet.

The Web provides a vast array of experiences including multimedia presentations, real-time collaboration, interactive pages, radio and television broadcasts, and the automatic "push" of information to a client computer. Programming languages such as Java, JavaScript, Visual Basic, Cold Fusion and XML are extending the capabilities of the Web. A growing amount of information on the Web is served dynamically from content stored in databases. The Web is therefore not a fixed entity, but one that is in a constant state of development and flux.

E-MAIL

Electronic mail, or e-mail, allows computer users locally and worldwide to exchange messages. Each user of e-mail has a mailbox address to which messages are sent. Messages sent through e-mail can arrive within a matter of seconds.

A powerful aspect of e-mail is the option to send electronic files to a person's e-mail address. Non-ASCII files, known as binary files, may be attached to e-mail messages. These files are referred to as MIME attachments.MIME stands for Multimedia Internet Mail Extension, and was developed to help e-mail software handle a variety of file types. For example, a document created in Microsoft Word can be attached to an e-mail message and retrieved by the recipient with the appropriate e-mail program. Many e-mail programs, including Eudora, Netscape Messenger, and Microsoft Outlook, offer the ability to read files written in HTML, which is itself a MIME type.

TELNET

Telnet is a program that allows you to log into computers on the Internet and use online databases, library catalogs, chat services, and more. There are no graphics in Telnet sessions, just text. To Telnet to a computer, you must know its address. This can consist of words (locis.loc.gov) or numbers (140.147.254.3). Some services require you to connect to a specific port on the remote computer. In this case, type the port number after the Internet address. Example: telnet nri.reston.va.us 185.

Telnet is available on the World Wide Web. Probably the most common Web-based resources available through Telnet have been library catalogs, though most catalogs have since migrated to the Web. A link to a Telnet resource may look like any other link, but it will launch a Telnet session to make the connection. A Telnet program must be installed on your local computer and configured to your Web browser in order to work.

With the increasing popularity of the Web, Telnet has become less frequently used as a means of access to information on the Internet.

FTP

FTP stands for File Transfer Protocol. This is both a program and the method used to transfer files between computers. Anonymous FTP is an option that allows users to transfer files from thousands of host computers on the Internet to their personal computer account. FTP sites contain books, articles, software, games, images, sounds, multimedia, course work, data sets, and more.

If your computer is directly connected to the Internet via an Ethernet cable, you can use one of several PC software programs, such as WS_FTP for Windows, to conduct a file transfer.

FTP transfers can be performed on the World Wide Web without the need for special software. In this case, the Web browser will suffice. Whenever you download software from a Web site to your local machine, you are using FTP. You can also retrieve FTP files via search engines such as FtpFind, located at /http://www.ftpfind.com/. This option is easiest because you do not need to know FTP program commands.

E-MAIL DISCUSSION GROUPS

One of the benefits of the Internet is the opportunity it offers to people worldwide to communicate via e-mail. The Internet is home to a large community of individuals who carry out active discussions organized around topic-oriented forums distributed by e-mail. These are administered by software programs. Probably the most common program is the listserv.

A great variety of topics are covered by listservs, many of them academic in nature. When you subscribe to a listserv, messages from other subscribers are automatically sent to your electronic mailbox. You subscribe to a listserv by sending an e-mail message to a computer program called a listserver. Listservers are located on computer networks throughout the world. This program handles subscription information and distributes messages to and from subscribers. You must have a e-mail account to participate in a listserv discussion group. Visit Tile.net at /http://tile.net/ to see an example of a site that offers a searchablecollection of e-mail discussion groups.

Majordomo and Listproc are two other programs that administer e-mail discussion groups. The commands for subscribing to and managing your list memberships are similar to those of listserv.

USENET NEWS

Usenet News is a global electronic bulletin board system in which millions of computer users exchange information on a vast range of topics. The major difference between Usenet News and e-mail discussion groups is the fact that Usenet messages are stored on central computers, and users must connect to these computers to read or download the messages posted to these groups. This is distinct from e-mail distribution, in which messages arrive in the electronic mailboxes of each list member.

Usenet itself is a set of machines that exchanges messages, or articles, from Usenet discussion forums, called newsgroups. Usenet administrators control their own sites, and decide which (if any) newsgroups to sponsor and which remote newsgroups to allow into the system.

There are thousands of Usenet newsgroups in existence. While many are academic in nature, numerous newsgroups are organized around recreational topics. Much serious computer-related work takes place in Usenet discussions. A small number of e-mail discussion groups also exist as Usenet newsgroups.

The Usenet newsfeed can be read by a variety of newsreader software programs. For example, the Netscape suite comes with a newsreader program called Messenger. Newsreaders are also available as standalone products.

CHAT & INSTANT MESSAGING

Chat programs allow users on the Internet to communicate with each other by typing in real time. They are sometimes included as a feature of a Web site, where users can log into the "chat room" to exchange comments and information about the topics addressed on the site. Chat may take other, more wide-ranging forms. For example, America Online is well known for sponsoring a number of topical chat rooms.

Internet Relay Chat (IRC) is a service through which participants can communicate to each other on hundreds of channels. These channels are usually based on specific topics. While many topics are frivolous, substantive conversations are also taking place. To access IRC, you must use an IRC software program.

A variation of chat is the phenomenon of instant massaging. With instant messaging, a user on the Web can contact another user currently logged in and type a conversation. Most famous is America On line’s Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat programs.

Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.

FAQ, RFC, FYI

FAQ stands for Frequently Asked Questions. These are periodic postings to Usenet newsgroups that contain a wealth of information related to the topic of the newsgroup. Many FAQs are quite extensive. FAQs are available by subscribing to individual Usenet newsgroups.

RFC stands for Request for Comments. These are documents created by and distributed to the Internet community to help define the nuts and bolts of the Internet. They contain both technical specifications and general information.

FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.

MUD/MUSH/MOO/MUCK/DUM/MUSE

MUD stands for Multi User Dimension. MUDs, and their variations listed above, are multi-user virtual reality games based on simulated worlds. Traditionally text based, graphical MUDs now exist. There are MUDs of all kinds on the Internet, and many can be joined free of charge.

Tips and Software to Find Storage Space on Hard Disk

2013-10-06T03:54:00.002-07:00

Sometimes if you’re hard drive storage capacity becomes full and you like to discover which folder is holding up the largest part space. Then you need to run such types of programs that will let you to find out the most occupy space and control it on your hard drives. Actually this type of problem considers like serious topic for a hard drive. It often gets full in no time and you are left surprising where are entire space gone. If you don’t sure where entire your space gone, then you need to run powerful software that will sniff out any space on your hard drive and describe you accurately how much storage space every folder takes.

Clean stored temp files first

If you don’t find out the where the Temp folder is stored, navigate to C:\Users<your_user>\AppData\Local\Temp and delete the content of the folder.

System tools for finding hidden space on your hard drive

There are a many freeware or license based software or tools that are designed for the reason of letting users to know what folders on their hard drives are occupying the most space. This software’s not only monitors your hard drive but also always find where all that space hides. At the bottom we are going to provides brief examples about such programs or tools that can let you locate space hogs on your hard drive.

TREESIZE FREE

This software is the simplest and user-friendly that you can use simply.TreeSize Free is a simple tool that will evaluate your partitions and show you a sign of how much every folder takes up. It is a simple interface that permits users to speedily browse folder and its sub-folders from any partition.

Selecting the partition from the menu at the top of the window and scan it. The whole process is completed in just seconds. The size of every folder is shown in MB and for multipart folder trees.

SPACESNIFFER

SpaceSniffer is small-weight software to find space hogs on your hard drive. It will permit you to scan any partition on hard drive and show a graphical look at how your folders are organized.

After the procedure completed, you will get all your folders in box-shapes, viewing the name and its size. By clicking on it, you will go one level down and see it’s containing folders.

Other Useful Software to find out Hard disk Space Hogs

WINDIRSTAT

SPACEMONGER

~~DISKSPACEFAN~~

FOLDERSIZE

Conclusion

With the help of above tools or software, you will always be capable to point out for big files that occupy a large quantity space on your hard drive. In additions, make sure that your hard drive’s is working properly.

10 Security Tips to Protect Your Computer and Network

2013-10-04T07:19:00.002-07:00

Whether you like it or not, hackers and virus coders have always been a few steps ahead of us. They devise new ways to take control of our devices and bank accounts. In an edifying

To check how secure your computer really is (and fixes, if it is not), take it out for a spin and undertake the following measures.

Plant a virus

This will sound absurd, and it probably is, but to check how effective your Anti-Virus suite is, you need to download a virus into your system. This is not any regular virus, but a very specific one. This is a part of the test called EICAR (European Institute for Computer Antivirus Research), which offers you a virus, and the catch is that if your Anti-Virus is efficient enough it will be able to detect that virus. Some Anti-Virus, like the one I am using (AVG) didn’t let the download to proceed. If your Anti-Virus does the same, it is a good thing, don’t sweat on it.

Remove saved passwords

Problem with so many great services available on the web is that you have to remember the username and password of all the accounts. To make things easier, most of us don’t mind letting our web-browsers save the login credentials. As convenient as it is, it arises some critical security concerns. Anyone locally or remotely can know your log-in credentials. It is that easy.

To remove your password from Chrome browser, go to the Settings, scroll down and from the Passwords and forms option, click on “Manage saved passwords.”. Delete all the entries.

Firefox users need to go the options, and under the security tab, they can remove all log-in credentials. You can use password management tools like KeePass and LastPass to save your time.

Check your browser plugins

There have been numerous cases in the past where the hacker got access to the victim’s computer through a malicious plug-in. Although there are many software, such as WinPatrol, Glary Utilities and many other which we have extensively covered in our weekly downloads articles, finding which extension is the crook can’t be done by them. To do that you will need to use BrowserCheck. It scans your browser and looks for the plug-ins you have installed on it. Additionally it will inform you if any of the installed plug-in is outdated.

Find who is on your WiFi network

If you don’t secure your WiFi network and make it password protected, you are simply inviting people to use your internet. Besides eating your data, with the help of many tools, the intruder can hop your WiFI network, if not get into your computer. Hence it is very important that you make your network password protected. To check who is on your WiFi network, download the tool Who is On My Wifi and the software will tell you all about it.

Don’t let anyone change your router’s settings

Many routers let any device which is connected to it configure its settings. All you need is the default IP address of your router, and the default password – both of which can be found very easily online. To stop anyone from changing your router’s settings, you will need to disable the port which is responsible for it and other remote management features. Depending on the manufacturer of your router, the step required to perform this will be listed in the router’s manual guide. While you are at it, also change the default password of your router’s page.

Disable data sharing through USB ports

Notably, some routers come with support for USB keys, which at times come handy, but mostly it is just another door for intruders to come in and plant and leave a virus inside it. If your router has a USB port too, you need to disable it. Depending on the manufacturer, you might see that option in the router’s webpage. Again, you need to check your router’s manual guide.

Check your Firewall

Windows has a built-in Firewall. But unfortunately it is not as strong as it should be. Take your firewall for a spin test. ShieldsUP is a nifty service that reviews your system’s firewall. With your consent it checks if your computer and router are vulnerable. If your PC is working fine, all its ports should be closed – which is the job of your firewall. If the website doesn’t find any vulnerable port, it means that your firewall is working fine.

Keep all the security modules up-to-date

Many non-Microsoft programs leave security vulnerabilities in your computer. To find such patches, and fix for it, Secunia PSI is the probably the best tool for this very task. Besides the aforementioned task, the software also checks if your Windows OS is up to date and has all the required security patches or not.

Reroute your DNS

If you want a simple solution to make all your browsing secure and well administered, you need to change the DNS settings of your network. OpenDNS is a very trusted service which offers you the same. The procedure to set it up is very easy and depends on the OS you are using. I can’t stress enough how much useful this service is. Once you have made the transition, which should take less than 10 minutes, you won’t have to worry about phishing and other common internet scams.

10 Tips to Make Internet Explorer a Better Web Browser

2013-10-04T07:15:00.000-07:00

The latest version of Internet Web browser (Internet Explorer) has come with new useful features. This browser has added a tons of changes and proved as the top-rated world browser than chrome and Firefox The new version shows few important improvements over its previous versions.

if you install latest version like Internet Explorer 11 in your computer then you may tweak a few settings and a group of third party apps in order to make it as an adorable and user-friendly browser.

Bring back the Content Advisor

In Internet Explorer 8 and 9 version, we had this great utility that let us curate lists of sites that we don’t want Internet Explorer to access. This option was however disabled in IE 10 and IE 11. To reinstate it, you need to go to the start menu, search for “group policy” and select “Edit group policy” from the result. You will now see a window appearing on your screen, double click on Administrative Templates, then follow this string: Windows Components | Internet Explorer | Internet Control Panel | Content Page. Double click on Show Content Advisor and inside the window, click on the radio button that says “Enabled”.

Once you have done that, open Internet Explorer, click on the settings, go to the “Content” tab, and from there you can set parental controls to other user accounts of your computer.

Kill that “View next page”

One thing that I completely dislike while reading articles on some websites is the need to click on “next page” to read the rest of the article. Many popular websites including the humor site – Cracked, and Technology publication – Forbes, have implemented this format. If you want to access the whole article in one go, IE10 and 11 have an option called “Flip Ahead” that lets you do just that. The website automatically detects if the article or slideshow has been partitioned and when you scroll down the page it gives an arrow icon to flip to the next page. This feature was first introduced in IE10 and was only available in the tile view of Windows 8. To make this option work in Desktop mode, you can go to the internet settings, and from the “Advanced” tab, click on ‘Enable flip ahead’.

Set Desktop Viewing as default

Windows 8 isn’t doing too well, one of the several reasons for this was the big change they introduced in the form of Tiles which replaced Desktop Viewing. People don’t like changes, I’m not going to quote any song lyrics to justify my point, but just trust me on that. Thankfully, Microsoft was gracious enough to provide option to switch back to the Desktop Viewing. However, it is not enabled by Default. To make this default, open Internet Explorer in Desktop View, then go to the settings and under thePrograms tab, click on the dropdown box and select ‘Choose how you open links’ and click ‘Always in Internet Explorer on the desktop’. Save the settings.

Quickly share things with friends

If you are using Windows 8, there is an option in IE10 and 11 to share things right from the browser itself. You need to select the part you want to share with your friends, right click on it and it will give you an option to email the selected content to your friends. Provide their email IDs, and this should do it.

Add support for WebM files

Backed by Google, WebM is the new video standard in town. Though pretty slowly, many websites, including YouTube is implementing this new format. While many browsers have in-built support for the current crowned and WebM’s competition H.264, the new codec isn’t yet friends with all popular web browsers, including and especially Internet Explorer. However, if you want to add WebM playback functionality to Internet Explorer, you need to install this tool.

The clutter free web

If you don’t like bogus distracting elements such as adverts, sharing buttons, etc., which the web comes along, IE11 has something nice to offer. The new version has this option called “Reading View” which essentially takes all the sidetracking elements out of the page and changes the orientation of the article to make the reading experience even better. However, it is only available in IE11.

For those of you who are running any lower version of IE, there is something for you too. You can use Readability, which more or less does the same thing, and in addition, allows you to save articles for offline viewing as well.

Block advertisers from tracking you

If you are running IE10 or beta version of IE11, the good news is that your browser is already blocking many types of trackers. Both the versions have Microsoft’s Do Not Track service enabled which disables many websites from tracking your online activities. However, Microsoft doesn’t curate any lists of blocked websites. You can check out the popular Tracking Protection lists where many trustworthy companies have complied lists of sites that usually track you. You can click on the “+” button at the right side of the lists to add the list to your IE’s database. If you are still using IE8 or 9, you can download Abine Do Not Track Me utility for Internet Explorer which also protects your from trackers.

Add password management tool on your browser

With so many services online, it has become hard to keep track of passwords of all the accounts we manage. This is where password management software come in handy. If you don’t want to use a separate application for managing passwords and would rather have something built in the browser itself, Dashlane is a pretty nice pick. The software has both desktop clients as well as add-on and extensions. It prompts you to put the credential of the sites you frequently visit, and once saved, it automagically fills all the forms and credentials from there after. The app has recently implemented two factor authentication which strengthens its security.

Update your browser

The latest version of the browser IE11 will be shipping with Windows 8.1 next month. If you can’t wait to get your hands on it, Microsoft has made its preview build available on their website. The new version is faster, more secure, and is bursting with tons of new features. The browser has full support for touch and responsive devices, it canlevitate and lets you check more than one tab side-by-side at once. Additionally, unlike all its previous versions, IE11 lets you open “unlimited” tabs.

If your computer is running on Windows 7, you can download the browser from itsdownload page.

IE on Chrome

There is no denying that there are many websites – mostly government and education portals that work best on Internet Explorer. But if you have made your mind that no matter what you are not going to switch from Chrome, perhaps the below Chrome extension will help you stick to your plan.

IE Tab uses the in-built IE engine of your Operating System to render pages on Chrome. To run any website in IE mode, click on its icon from the extension bar (right next to address bar) and it will fire up a separate page for it. Additionally, you can also go to its settings (by right clicking on its icon) and add the websites you always want to be run in IE mode.

Guide to advantages of .Net Framework

2013-09-12T07:45:00.002-07:00

1. What are the advantages of using .NET ?

Consistent Programming Model:

Different programming languages have different approaches for doing a task. For example, accessing data with a VB application and a VC++ application is totally different. A developer has to know bothdifferent techniques to do the task. In case of .NET Environment, for the same example, displaying data from database in a grid accessing data with a VB.NET and a C# is very similar except slight syntactical differences. Both the programs use the System.Data namespace, establish a connection with the database and run a query and displays the data on a data grid.

Language Independence:

Language Independence means the developer has the independence to code one module of an application in one language and other module of same application in other language. This language interoperability can help in code reuse and improve the efficiency of the development process.

No versioning Problem - Easy Application Deployment and Maintenance:

The .NET Framework makes deployment of applications easy. Commonly, to install an application all we need to do is, copy the application along with the components it requires into a directory on the computer. The .NET handles the details of locating and loading the components an application needs, even if several versions of the same application exist on the computer. The .NET ensures that all the components the application depends on are available on the computer before the application begins to run.

Improved Security:

The .NET Framework provides several mechanisms for protecting resources and code from unauthorized users:

· ASP.NET Web Application Security provides a way to control access to a web site by comparing authenticated permissions with File System permissions for proper authorization.

· Code access security uses permissions to control the code accessing protected resources and operations. The computer systems are protected from suspicious mobile code and provide a way to run mobile code to safely.

· Role-based security provides information needed to make decisions about user’s permissions.

Support for Web Services:

Web services are remote databases and programs, which access other computers to read the data files. Web services provide many built in Base Class library facilities which open up a whole new world of information for users.

Dynamic Web:

Content that changes with the user and user preferences is an example of dynamic web content. Dynamic web content is easier to create with .NET. ASP.NET and Visual Studio.NET allow developers to create dynamic web much easier than IIS and ASP technologies.

Visual Studio.NET:

Visual Studio.NET is the Microsoft application and interface for programming in .NET. Visual Studio .NET provides all the programming advantages mentioned so far. This development environment has extensive set of ready to use controls, good debugging facilities, easy and simple programming features and vast set of .NET Base Classes.

1. Explain different features of .NET.

2. What is .NET ?

List the advantage of .NET frame work.

Consistent Programming Model:

Language Independence:

No versioning Problem - Easy Application Deployment and Maintenance:

Improved Security:

The .NET Framework provides several mechanisms for protecting resources and code from unauthorized users:

ASP.NET Web Application Security provides a way to control access to a web site by comparing authenticated permissions with File System permissions for proper authorization

· Role-based security provides information needed to make decisions about user’s permissions.

Support for Web Services:

Dynamic Web:

Visual Studio.NET:

1. Explain .NET framework?

The .NET Framework is the foundation on which you can design, develop, and deploy applications. It is the core of the .NET infrastructure. It exists as a layer between the .NET applications and the underlying operating system. The .NET Framework encapsulates much of the basic functionality, such as debugging and security services, which was earlier built into various programming languages.

2. What is unsafe code? Explain.

Unsafe code refers to the code that is processed with low security levels. There are situations where access to pointer types becomes a necessity. For example, interfacing with the underlying operating system, accessing a memory-mapped device, or implementing a time-critical algorithm may not be possible without access to pointers. To address this need, C# provides the ability to write unsafe code. In unsafe code, it is possible to declare and operate on pointers, to perform conversions between pointers and integral types, to take the address of variables, and so forth. In a sense, it is like writing C code within a C# program. Unsafe code must be clearly marked with the modifier unsafe, so developers cannot possibly use unsafe features accidentally. When CLR finds this unsafe modifier, the execution engine works to ensure that the unsafe code cannot be executed in an untrusted environment.

3. Explain the following:

b) JIT compiler.

JIT compilation converts IL into its native machine code. The name JIT is because it compiles portion of code as and when required at runtime.

4. How .NET remoting different from web services and DCOM ?

The differences between .NET Remoting and Web services are listed as follows:

· ASP.NET based Web services can only be accessed over HTTP, whereas the .NET Remoting can be used across any protocol.

· Web services work in a stateless environment where each request results in a new object created to service the request. .NET Remoting supports state management options and can identify multiple calls from the same client.

· Web services serialize objects through XML contained in the SOAP messages and can thus only handle items that can be fully expressed in XML. .NET Remoting relies on the existence of the metadata within assemblies that contain information about data types. This limited metadata information is passed about an object, when it is passed by reference.

· Web services support interoperability across platforms and are good for heterogeneous environments. .NET Remoting requires the clients to be by built using .NET, which means a homogeneous environment.

The difference between .NET Remoting and DCOM is listed as follows:

· DCOM relies on a proprietary binary protocol that not all object models support. It also wants to communicate over a range of ports that are typically blocked by firewalls. However, .NET Remoting supports different transport protocol formats and communication protocols. This allows .NET Remoting to be adaptable to the network environment in which it is being used.

1. Write a program in C# to display “Welcome to C Sharp”. Explain the program.

The C# program is as follows:

using System;

namespace ConsoleApplication1

{

class Welcome

{

static void Main()

{

System.Console.WriteLine("Welcome to C Sharp");

Console.Read();

}

The important points to be noted in this program are:

· Main method: Program execution begins with the Main method.

· Input and output: The WriteLine function displays the string on the standard output device.

· Compilation and execution: To compile the program, enter the following command:

cscWelcome.cs

To execute the program, enter the following command:

Welcome

2. How does C# supports multiple inheritance?

C# directly does not support multiple inheritance. But we can use this feature by using interface. Interface supports multiple inheritance.

interfaceIControl

{

void Paint();

}

interfaceITextBox: IControl //ITextBox inherits IControl

{

voidSetText(string text);

}

interfaceIListBox: IControl //IListBox inherits IControl

{

voidSetItems(string[] items);

}

interfaceIComboBox: ITextBox, IListBox {}

the interface IComboBox inherits from both ITextBox and IListBox. Classes and structs can implementmultiple interfaces.

1. Define the following :

CLR, CTS, CLS, Intermediate language.

CLR:The CLR loads and executes the code. Code management is a fundamental principle of the runtime. It also provides services such as memory management, thread management, remoting, type safety, code security, and robustness.

CTS:The CTS is a standardized set of basic data types. This system provides a way to language interoperability. An object implemented in one .NET supported language can call an object implemented in another .NET supported language.

CLS: Common Language Specification (CLS) is a set of rules for basic language features that have been defined to enhance and ensure language interoperability.

2. Give the classification of comman data type system.

3. What is the function of CTS ? Explain the classification of types in CTS with a diagram.

The CTS defines how types are declared, used, and managed in the runtime. It is important for language interoperability. The CTS performs the following functions:

· Establishes a common framework that enables cross-language integration, type safety, and high performance code execution.

· Provides an object-oriented model.

· Defines rules that languages must follow, so that different languages can interact with each other

CTS can be classified into:

· Value types

· Reference types

The following diagram illustrates type classification.

Value types directly store data in the variable. Value types can be built-in type, user-defined types, or enumerations.

Reference types store a reference to the data's memory address. Reference types can be self-describing types, pointer types, or interface types. Self-describing types are further split into arrays and class types. The class types are user-defined classes, boxed value types, and delegates.

All types derive from the System.Object base type

4. What is operator overloading? Explain with an example.

Operator overloading refers to loading an operator to perform different operations on different data types on different contexts. To overload an operator in a class, one defines a method by using the 'operator' keyword.

The following program uses operator overloading to create a complex number class ComplexAdd that defines complex addition. The program displays the imaginary and the real parts of the numbers and the addition result using an override of the ToString method.

// complexAdd.cs

using System;

public struct ComplexAdd

{

public int r;

public int img;

public Complex(int r, int img)

{

this.r = r;

this.img = img;

}

// Declare which operator to overload

public static ComplexAdd operator +(ComplexAdd c1, ComplexAdd c2)

{

return new ComplexAdd(c1.r + c2.r, c1.img + c2.img);}

// Override the ToString method to display a complex number in a required format:

public override string ToString()

{

return(String.Format("{0} + {1}i", r, img));}

public static void Main()

{

ComplexAdd var1 = new ComplexAdd(5,3);

Complex var2 = new Complex(6,2);

// Add two Complex objects (var1 and var2) through the

// overloaded plus operator:

ComplexAdd total = var1 + var2;

// Print the numbers and the sum using the overridden ToString method:

Console.WriteLine("First complex number: {0}",var1);

Console.WriteLine("Second complex number: {0}",var2);

Console.WriteLine("The sum of the two numbers: {0}",total);}}

Output

First complex number: 5 + 3i

Second complex number: 6 + 2i

The sum of the two numbers: 11 + 5i

Tips to Start Any Internet Browser in Private Browsing Mode

2013-09-12T07:37:00.001-07:00

Today’s Private browsing mode is the best option to protect entire privacy over internet. It avoids you to save your visit history, search history, cookies and other confidential data during browsing sessions. If you like always start your browser in private browsing mode then this feature is available in almost all leading browser like Chrome, Firefox, Opera and etc.

While a good number of people will not wish to use private-browsing mode permanently due to some personal reasons. To get started this feature in any browser, you need to sign in to your browser which you use always. Now check out the tips how to start private browsing mode always in following browser?

Google Chrome

· At first you need to turn on Google Chrome’s incognito mode. Generally the chrome’s shortcut is located either on your desktop, start menu or taskbar. So you need to insert a command-line option to its shortcut.

· If you are using chrome task bar shortcut on Windows 7 or 8 then you will have to right-click on the Google Chrome icon on your task bar and select Properties.

· Under Google Chrome Properties window, click on Shortcut tab. Here insert a command “incognito” after single space to the end of the box.

· Next click OK button after inserting this command-line.

Thus Google Chrome will now begin in incognito mode while you will start it using taskbar shortcut. If you use additional shortcuts (desktop) to begin Google Chrome then you will need to change its properties with above same method.

Mozilla Firefox

Firefox lets you to automatically turn on private-browsing mode using its options window. To do so,

· Click on the Firefox menu button at the top side and select Options.

· Next click on the Privacy tab under options window. Here go to History tab and select Never remember history option from drop –down list.

· Now Firefox will use private-browsing mode but it will not present its normal private-browsing interface.

Internet Explorer

You need to add a command-line option to Internet Explorer shortcuts properties in order to enable InPrivate browsing mode automatically. The shortcuts of Internet Explorer are located either on the desktop or taskbar. To do this,

· At first search for Internet explorer shortcut (for example taskbar) which you want to start.

· Next right-click on it and select Properties. Within Windows 7 or 8, right-click on the Internet Explorer icon and select Properties.

· Here you have to insert a private word to the end of the target box (see below screenshots carefully).

· Finally click OK button.

Thus Internet Explorer will now run with InPrivate browsing mode while you start it through taskbar shortcut. If you use other shortcuts to run Internet Explorer then you need to change with private word to its properties.

Opera

Opera also provides a command-line option to switch on private-browsing mode. To do so,

· Look for your Opera shortcut either from desktop or task bar Next press right-click on it and select Properties.

· Next insert newprivatetab word to the end of the target box.

· At last Click OK button.

Now Opera will start a private-browsing tab when you start with this shortcut.

Conclusion

Keep in mind that all above browsers are unable to store login history, websites favorites or any other type of data like visit history once you switch on private mode. So browser private mode feature are both good thing and annoyance. In case If you like to restore any of these changes then you can remove command –line word to the shortcuts which you have added before. For Firefox browser, you have to select the Remember history option.

Introduction to Web Programming

2013-09-09T06:34:00.000-07:00

1Differentiate between Java & Java scripts.

Java :-

Java Programming language, is an OOP Language and development environment, application environment, deployment environment. It is standalone programming Language that do not require a web browser to execute.

Java script:

It is a contained in the HTML source of webpage. It controls document appearance and content.

It also manipulates embedded images and it also interacts with Applets. Its advantage is that it is simplified,

it doesn’t have to be compiled and the source code resides within our HTML document.

1 What are cookies? And why are cookies used for?

Cookies are small text strings you store on a user's computer. Cookies store information for tracking users in name-value pairs. When you first visit a website it may store a cookie on your computer. Next, when you again visit the site it may read or manipulate the value of the cookie and perform an action based on it. For example, if a site allows you to customize the color of the user interface, it may set the color selected by you in a cookie on your computer and read the color value when next time you request the page of the website. The page can them be displayed in the color stored in the cookie.

2What is XML? Give the XML document.

XML is a simple, common format for representing structured information as text. You can create your own tags to define and structure data, and transmit it. The basic syntax of XML is extremely simple. As with HTML, XML represents information as text using tags to add structure. A tag begins with a name in between angular brackets (<>). In XML, every tag must have a closing tag. An opening tag, closing tag and any content in between are collectively referred to as an element of an XML document. Elements can contain other elements but they must be properly nested. Elements can also contain text or a combination of elements and text.

Best Online Services to Sync Files between Computers Over Internet

2013-09-09T06:30:00.001-07:00

Copy files from one computer to another is extremely tiring job. Without knowing proper methods, sometimes it can take unlimited periods of time. An easiest solution to fix this type of difficulty using syncing applications which mostly perform whole job for you in short periods of time. There are three kinds of sync solution available between two or more computers or devices for example,

Particular Sync applications
Local network sharing
Cloud service (Google Drive, SkyDrive, DropBox)

The major variation between these two sync solutions is that through a cloud services you will also have a backup copy reserved online. Besides those preferring the cloud solution will perhaps have to subscribe a paid account if they have to save unlimited files as backup.

Tips to Sync files between two computers Using Sync Software

SYNCTOY

SyncToy is windows OS based freeware sync software and comes from Microsoft. It lets you to synchronize files between computers with same network. The software is very customizable, user-friendly and helps users to do most processes like copying, transferring and synchronization only with few steps. Here’s how to get advantages of sync features from this software?

At first, download SyncToy from the official Microsoft site and install it to your computer.
Next click on Create New Folder Pair button.
Now select the path of the left folder and the right folder. The left folder stands for the path to the folder that you wish to be synchronized and the right folder denotes the path to the target folder on your system.
Next you will get a new screen with three possible action buttons like Synchronize, Echo and Contribute. The last two buttons only copy the new and updated files from the left folder to the right folder. While Echo button will make carbon copy or clone every delete actions from left to right.
To start the syncing actions, select the Synchronize action button. Now, set a folder name for the synced folders and click on Finish button.

· Finally, click on Run button to start the synchronization.

FREEFILESYNC

FreeFileSync is simple sync application in order to sync all types of files. The application comes with a folder comparison and synchronization tool that will do the complete job once the user finishes these next steps.

Firstly Download FreeFileSync from here.
Launch the application and a folder which you like to clone information from and its destination.
Now Compare the files and choose desired synchronization settings.
Next press the Synchronize button.

BITTORRENT SYNC

BitTorrent Sync is freeware sync software that comes through recognized torrent client. It lets you to sync files without difficulty and strongly between computers by the peer-to-peer protocol. The benefit of this software is that none of your files are syncing to cloud but directly to the other computer. Remind that both computers must be connected to internet during perform the syncing operation.

How to setup BitTorrent Sync Software?

· Firstly, download BitTorrent Sync software from here.

When you begin this software for the first time, you have to select the path for the synced folder.
BitTorrent software provides you a secret code. This code will be used further on the other computer to connect the two synced folders.
As soon as all sync operations are configured successfully, the syncing procedure will automatically start

Note:

One more popular sync software which you may also test is known as GOODSYNC

Tips to Sync files between two computers using local network sharing

These days, it is fairly simple to have above one computer in a home. So, transferring files between them becomes vital. Sharing a folder is an easy process but not everyone familiars how to get started it. So read the steps at the bottom how to correctly share a folder on Windows OS?

· At first, right click on the preferred folder which you want to share over network.

· Next select Share with option from right panel and choose to share it with Specific People option. Now go to drop-down panel and select either a particular user option or everyone option. Almost, everyone option lets you to access the shared files to connected network.

· At last click on Share option and wait until the process finishes.

· To access the just now shared folder in the network, now search your computer’s name in the Network section and see the files within shared folder.

Tips to Sync files between two computers using Cloud Service

DROPBOX

Dropbox is a well-known cloud based service that allows users to access most used files like photos, docs, videos from anyplace on the web. It offers free service that also supports synchronization productivy. An additional exciting feature of Dropbox is that it can also sync Smartphone. So, if you wish to use Dropbox on your Smartphone, the official app is available for Android or iOS.

GOOGLE DRIVE

Google Drive is an integral part of Google’s search engine which now offering free cloud and DOC service together for all Gmail users. Currently Gmail desktop app comes for most every platform like Windows, Mac, Chrome OS, Android and iOS. The download link of Gmail desktop app is here.

The most remarkable feature of Google Drive lets to use free accounts with 5 GB of cloud storage. More details here.

BOX

Box is also admired online cloud storage service that supports sync features. It provides fully online service and can be used for creating and editing documents directly in the browser. The Box cloud service offers desktop app for Windows, Mac which is used only to sync files. Synchronization can also be made directly from the web browser.

You may check out the another excellent alternative as Space Monkey

Typing Tutor App for Windows 8 to Improve Typing Speed

2013-09-08T05:37:00.004-07:00

Typing Tutor is an interesting windows 8 app which is used to improve your typing speed. This App assists you to improve your typing skills and also tests your speed and accuracy in typing. It offers you a set of five different courses each consisting of various stages. Working with this app is very easy and simple. The interface of this app is designed in a very simplistic manner to keep the things simple and easy to use.

How to use Typing Tutor app on windows 8 ?

After installation of this app, a window will pop up which is the welcome page of this app. Press Go to move inside this app. A new screen will come out on your screen. This screen shows you two option:

Start Course:This section lets you do the different things to improve your skills.

About: This part basically informs you about the different features present in this app.

Click on the Start Course option to do the main things of this app. Once you click on this option, a list of five different options will be presented in front of you. They are described below:

Home Row: This section is designed to improve your skills on the middle rows present in the keyboard.

Top Row: This section is designed for improving your typing skills for the alphabets present in the first row of your keyboard.

Bottom Row: This section improves typing skills on the alphabets present at the bottom row.

Shift Key: This section teaches you the proper usage of the shift key on your keyboard. It also guides on when to use right shift key and left shift key in different situations.

Number Pad: This section teaches you the proper usage of keyboard’s number pad. It also helps you in increasing your speed when you are using numbers in your writings.

As soon as you fully understand which portion of yours is weak, you could move to the section you wish. Select the section about which you want to know the details. Selecting any option will opens a new screen where you could select the complexity of level. Choose the level. Then it shows you a string of random letters on your screen. Type the word present on the screen. If you typed right, it would turn into Green otherwise Red. You could see your score in the blue box at the top.

Best Features of Typing Tutor

Simple Interface.

Free and user-friendly.

free from Ads.

Optimized to boost typing skills.

Download Typing Tutor App

Total Call Recorder App for Android to Record Incoming and Outgoing Calls

2013-09-07T08:04:00.004-07:00

Total Call Recorder is a free app of android devices used to record calls. This app works completely flawlessly. You can record any call with Total Call Recorder using Android Phone with this app very easily. It could also run in the background letting you do multiple tasks. It makes sure that you don’t miss any call because of this app. The interface of this app is very smooth and attractive. The developers have made sure that no stone has been left unturned to make sure that this app provides a very smooth experience on your Android device. On my test device, I experienced no lags or crashes whatsoever while running this app.

The simple, intuitive interface with a huge number of features and controls, makes it the must have for every Android users and smartphone vendors. A screenshot of this app is shown below:

You could have this app as a free download via Google Play Store or you could simply visit to the link provided at the last of this article.

How to use and play with Total Call Recorder app

Once you have installed this app on your android device, a splash screen will pop up in front of you which provides a professional look on your device. It generally cuts the annoyance of a splash screen which might stay for a long period at the same time. When this splash screen disappears from your screen, a new window will comes out. This is the main interface of this app. This main interface is divided into panels as shown in the above screenshot. The two panels are described below:

1. Recording- This is the main feature of this app. It allows you to record incoming calls incoming as well as outgoing. There are special icons for two types of calls. There is ablue arrow facing towards the phone for incoming calls, green arrow going upwards from the phone is for outgoing calls. These two different icons let you know which call you are recently recording. You can pre-decide whether you are going to record it or not. You could also click on the recording option to record the call which is going on too if you haven’t chosen the automatically on button. The recorded call could be listened once you are done with the recording by clicking on the Play option.

2. Settings - This section provides you all the customization settings which you are going to do for your android devices. This is a very simplistic as well as with no confusing options present in it. There is only one option present here which asks you for On or Off option.

In the screenshot above, you could see the two sections described above. Settings On option start to record any calls automatically on your behalf. You could also bring up additional menu from the bottom of the screen by clicking on the options soft key on your android device.

Key Features of Total Call Recorder App

1. Completely Free App.

2. Intuitive and Easily understandable Interface.

3. No Promotion of Ads.

4. No Complex Settings, Easy Configuration.

5. Proper list of recording of outgoing as well as incoming calls.

6. Once set on ON position, it automatically records call.

Conclusion

Total Call Recorder is a fantastic app allowing you to record calls. It could automatically record any calls for you. No promotion of ads lets you do the recording of calls in an efficient manner without any disturbance. It is a worth trying app.

Download TotalCall Recorder here

10 Interesting things about Android, iPhone,

2013-09-07T08:01:00.002-07:00

We use our smartphones ( Android, iphone, Blackberry) normally for calling, messaging, surfing internet, downloading songs, photos, videos etc. These days smartphones have become a magical machines with a lot of exciting apps which could transform them into musical instruments or games consoles, business machines or cat video players. However, did you know you could do a lot more uses with your smartphone. It might be that you are unaware of all these amazing things.

1. Remote Control Using your Smartphone

There are some fantastic apps present in the App store of your android devices. One beautiful feature among them is that you could use your smartphone as remote control device. To track of each one is a big task, and to track of all remotes to establish control over them, is more tuff. Remote Control is a solution that’s been around for some time. Yeah, this is true. you could control different gadgets using your smartphones handsets like: DVR of your computer, a high end digital Camera etc. This feature could also be used for impressing your friends by remote controlling keynote presentations and the PowerPoint.

2. Saving the Rainforests

Using your smartphones, you could use one of its nice application and i.e. detecting chainsaws. It is a serious business. The non profiting organisation in Indonesia Rainforest Connection wants to use donated Android phones to detect illegal logging. According to the scientists, the new phones are outfitted with the solar panels which is designed to take the advantage of the brief periods when light reaches the forest floor. The microphones present with the officers is turned ON all the time, and the software present in the smartphones listens for any growl of a chainsaw. If it hears any such sound, it triggers an alert all over the forest.

3. Stitch photos together

Using the Photosynth application of smartphones, you could easily stitch photos together and create visual panoramas. This app could also be used to create a 360 degree images to show off a house or an apartment or to construct stunning panoramic views. 3D modelling could also be performed using this app.

https://itunes.apple.com/us/app/photosynth/id430065256?mt=8

4. In the detection of chemical warfare attacks

US department of homeland Security is trying to use smartphones as anti-chemical warfare softwares. It aims to persuade manufacturers to equip the recent smartphones to be launched with some of the cheap chemical sensors which could be later used a anti chemical warfare. A buck of sensors are going to be used. If lashed with this new types sensors, your smartphones could detect from certain leaks to gas attacks as well. However, this idea has not been implemented yet as the US Company is still figuring whether this app is practically feasible in a smartphone.

5. Live TV

Live TV is now playing a crucial role in our daily lives. Now, we don’t need to sit before a Television for watching our favorite channel or serial. We could see all the left episodes as soon as we are free from our work. All we have to do is to have a live TV on our laptop or PC. These days, smartphones are too providing live tv which is really an exciting thing. A lot of the local service providers as Comcast, Verizon and others as well as telephone providers (Sprint) presents apps to live streaming content to a smartphone. You could easily download some apps like netTV or TVUPlayer. The image as well as sound quality both are of good quality in these apps.

Download Live TV here:

http://www.nettv.com.mt

http://www.tvunetworks.com

6. Warnings about speed traps

You could use the Trapster app in your smartphones to get the proper knowledge about the speed traps, hidden cameras and many other roadway hazards. The speed with which your vehicle is moving could also be monitored in a proper way. This app gives you an early warning of red lights as well as other potential dangers. You could get this app from the link provided below:

http://www.trapster.com/

7. Monitoring Heart Rate using smartphones

You could download an amazing app from the link provided below by Azumio. It is compatible with your smartphones. This is generally used for your smartphone’s camera which could be used to measure your pulse and calculate the heart rate of your body. It could also be used for measuring the fat burning ability as well as how your heart rate recovers after exercise quickly. This is one of the fantastic app and its results are completely reliable.

https://itunes.apple.com/us/app/instant-heart-rate-heart-rate/id395042892?mt=8

8. Have an Eye on your kids

Tracking your child is a very good thing these days to save them from upcoming different types of problems. There are various types of apps present in the market which allows you to have an eye on your kids activities without any suspicion. You could remotely check in on the whereabouts of another smartphone using GPS tracking. There are some apps for the smartphones which could send you an alert when that smartphone enters or leaves any designated area. Some of the apps with their names are written below:

http://www.verizonwireless.com/wcms/consumer/products.html

https://itunes.apple.com/us/app/find-my-iphone/id376101648?mt=8

9. Smartphone Metal detectors

There comes some sensors for your android device which after installation could be used as a metal detectors. It could be very handy to use a metal detector in your pockets. It helps in many situations like: when you, as an emergency physician, have an unconscious patient come in and you need to know whether he has an implant. It helps you in a lot of places. There is one weakness here and i.e. the sensors are not made to detect metals from a long distance which if implemented could be of greater use. However, this is an interesting example of the useful unintended consequences of having this app in your smartphone.

10. Stop Embarrassing phone calls

It is sometimes that we wish not to contact certain persons for some period of times without letting him know that you have restricted his numbers. You could do this thing right from your handset using certain application of your smartphones like Designated Dialer. You could simply block some persons by whom you don’t want to receive calls or messages. This could be used by girls for blocking their ex-boyfriends calls as well as some other calls too. However, note that unlocking any blocked number requires a mini quiz to be passed out or sobriety test.

https://itunes.apple.com/us/app/designated-dialer/id300729414?mt=8

Conclusion

Besides all the above mentioned 1o amazing things, there are some other surprising application of smartphones too like: checking in for flights (no more printing out tickets at home or waiting annoying lines!), setting your DVR remotely (if you’re local provider allows it), and ordering food on my way home so dinner’s waiting for me (Seamless Mobile has been a lifesaver for me!). For some of the more advanced functions of a smartphone, you may have to purchase add-ons. That’s what all of the following functions have in common. All the above mentioned things are tried on different smartphone and is reliable. Use them and get to know about them in details.

How to Stop Automatic App Updates in Windows 8.1 Preview and RT

2013-09-03T07:37:00.001-07:00

Windows 8.1preview version is the first update of windows 8 version. It is presently available with free download at Microsoft download portal. Windows 8.1 has provided a welcome feature to update modern-style apps automatically. This type of feature is also found already on your Smartphone for instance when many installed apps are updated in the background itself. Most windows 8.1 users would like to start their apps update automatically in the background.

But, sometimes it can be irritating when you find lists of update notifications of all modern-style apps. Because new app update can consume more internet data if you are using limited internet pack.

Tips to disable automatic app updates on Windows 8.1 and RT

· Start the Windows Store and bring up the charms bar.

· Click on Settings and select App Updates.

· On the next screen you have to move slider to no option with purpose to turn the automatic updates off. Here you can manually test for updates also.

· After configuring above settings, you will get a number of new app update notifications on the Windows Store tile. Here you can select app updates which you like to start or deny.

Conclusion

Microsoft has revealed a great feature for the average user epically for windows 8.1. It is not only user-friendly for tech bloggers and power users, but if you’re an IT admin, you might need to know what’s new in the update to make sure it’s not going to break other things you’ve deployed on the company network.

Complete Guide to Web Programming - Step 1

2013-09-03T07:25:00.000-07:00

What are text nodes?

If a node contains text, it is represented as a text node. For example, in"This is the initialtext., there are text nodes "This is the", "initial", and "text".

What is CGI? Give examples of CGI application.

Common Gateway Interface is a specification, which allows Web users to run programs from their computers. CGI is not a programming language but rather a specification that allows programs and scripts written in other language to be run over the Internet.

What is Query String?

QUERY_STRING:The query information passed to the program. It is appended to the URL with a ?when the browser sends it to the server. The name value pairs are then stored in this environment variable.

What is Extra Path Information?

Besides passing query information to a CGI script, you can also pass additional data known as extra path information as part of the URL. The server gauges where the CGI program name ends; anything following that is deemed as extra path information and stored in the PATH_INFO environment variable. For example the following line calls a script with extra path information:

What is a web server?

The Web server is the software responsible for accepting browsers' requests, retrieving the specified file or executing the script, and returning its content to the browser. Popular Web servers include Tomcat, Apache, and IIS.

List out differences between web server and application server.

The main differences between Web servers and application servers are:

A Web server is where Web components are deployed and run. An application server is where components that implement the business logic are deployed. For example, in a JSP-EJB Web application, the JSP pages will be deployed on the Web server whereas the EJB components will be deployed on the application servers.

A Web server usually supports only HTTP (and sometimes SMTP and FTP). However, an application server supports HTTP as well as various other protocols such as SOAP.

In other word

Difference between AppServer and a Web server
(1) Webserver serves pages for viewing in web browser, application server provides exposes business logic for client applications through various protocols

(2) Webserver exclusively handles http requests. Application server serves business logic to application programs through any number of protocols.

(3) Webserver delegation model is fairly simple, when the request comes into the web server, it simply passes the request to the program best able to handle it(Server side program). It may not support transactions and database connection pooling.

(4) Application server is more capable of dynamic behavior than webserver. We can also configure application server to work as a web server.Simplyapplication server is a superset of web server.

1 Describe role of deployment descriptors.

A deployment descriptor is an XML document that defines all the components of an application along with related information such as initialization parameters and container managed security constraints that you want the server to enforce. This file helps the server to know crucial details about the application.

1What is a war file? Give its importance.

WAR or Web Application Archive file is packaged servlet Web application. Servlet applications are usually distributed as a WAR files.

WAR file (which stands for "web application archive" ) is a JAR file used to distribute a collection of JavaServer Pages, servlets, Javaclasses, XML files, tag libraries and static Web pages (HTML and related files) that together constitute a Web application.

How to specify session time out in Web.XML?

You can specify session timeout in the <session-timeout> attribute of the <session-config> element. For example, to specify a session timeout of 30 minutes use:

<session-config>

<session-timeout>30</session-timeout>

</session-config>

Complete Guide to Web Programming

2013-09-03T07:11:00.000-07:00

What is Web

A Web is a complex network of international, cross platform, and cross cultural communicating devices, connected to each other without any ordering or pattern.

What is the difference between intranet and internet

Internet and Intranet are both networks. However, the Internet is a network of networks, involving all communicating devices over the Web. However, an Intranet is limited to the users, machines, and software programs of a specific organization.

Describe HTML tags and elements in briefly

An HTML tag defines the markup for a particular content in an HTML page and is represented within angular brackets. A start tag is represented as <tag_name> and an end tag is represented as </tag_name>. Most tags in HTML are in pairs of start and end tag. Only some tags such as do not have an end tag.

An element contains a start tag, an end tag, and the content, which is marked up by those tags. The content in an element may comprise of data as well as nested tags. For example, the following is an HTML element:

<body>

This is a nested tag

</body>

An HTML page starts and end with <HTML></HTML> tags, marking the beginning and end of an HTML page. A page can be divided into the header and the body. The <HEAD></HEAD> tags represent the former and contain header information, which is not displayed in the browser window. The <HEAD></HEAD> tags also contain the <TITLE></TITLE> tags, which contain the text that will be displayed in the title bar of the browser window when the page is opened.

The <BODY></BODY> tags comprise the body element of an HTML page. The content with the <BODY></BODY> tags is displayed in the browser window.

What is Java Script?

JavaScript is a scripting language used to make interactive web pages. It is mostly used as a client side scripting language. Its uses include:

List out uses of Java Script.

Control document appearance and content
Control the browser
Interact with document content
Interact with user
Read and write client state with cookies
Interact with applets
Manipulate embedded images

What are the difference between HTML and DHTML

HTML is a markup language used to create static web pages. DHTML on the other hand is not a language by itself but a combination of different technologies such as HTML, CSS, JavaScript, and DOM. It is used to create dynamic pages.

Computer Basics ( Input Device and Output Device)

2011-05-19T21:05:00.000-07:00

Basic Components of a Computer

Working of Computer

• Computers follow the basic principle of the Input-Process-Output (I-P-O) cycle.

• Input refers to data or instructions given to the computer.

• Output refers to the result given by the computer.

• Process refers to the work done by the computer to obtain the output.

Input Devices

• The input is given to the computer by means of input devices.

• Keyboard, Mouse, Scanner, Barcode reader, Web cam, and Microphone are some of the commonly used input devices.

Keyboard and Mouse Connectors

• The keyboard and mouse are connected to the computer by using PS/2, serial ports or a USB port.

• The PS/2 keyboard and mouse ports are 6-pin ports.

• To avoid confusion between the two ports, the system case usually has symbols and colour coding. The green colour port is used for mouse and the purple colour port is used for keyboard.

Keyboard

• A keyboard is used for typing text into the computer.

• A computer keyboard is similar to a typewriter keyboard but has some additional keys.

• The most commonly available computer keyboard has 104 keys.

• Based upon their connection to the motherboard, keyboards are classified into:

– PS/2 keyboard

– USB keyboard

– Wireless keyboard

Mouse

• Mouse is an input device.

• It is used to point at and choose things displayed on the monitor.

• A mouse may have two or three buttons.

• The most commonly used ones have two buttons – left mouse button and right mouse button. The left button is the most frequently used button.

• Based upon their connection to the motherboard, mouse is classified into:

– PS/2 mouse

– Serial mouse

– USB mouse

– Wireless mouse

• Based on the technology used, mouse can be broadly classified into two categories. They are namely,

– Mechanical mouse

– Optical mouse

• Wireless Keyboard and Mouse

• Wireless keyboards and mice are powered by small, light weight batteries.

• The media used to connect to the computer can be through Radio Frequency (RF) waves, Infra Red (IR) signals or through Bluetooth or Industry standard RF.

• Wireless mouse or keyboard using infra red signals for communicating with the computer need to be in “line of sight” in order to work.

• Wireless mice or keyboard using radio frequencies for communication requires two components: a radio transmitter and a radio receiver.

• Scanner

• A scanner is a multimedia input device that uses light to read printed information including text, images and bar codes and transfers it to computer in digital format.

• Scanners can be categorised as:

– Flatbed scanners

– Sheet-fed scanners

– Handheld scanners

– Drum scanners

Web Camera

• Web camera or Webcam is a small camera attached to a computer.

• Webcams connected to PCs can act as Web-accessible cameras with certain software.

• Webcam can be used for one-to-one live video communication over the Internet, video conferencing and so on.

• It can capture short videos in predefined length or still images. The captured files can be saved locally and uploaded to an Internet server.

Microphone

• A microphone is used to record voice or sound. This recorded sound can be stored in a computer in the form of digital signals.

Barcode Reader

• A barcode reader is an electronic device which optically scans a barcode and translates the data contained in the barcode pattern into data which can be used by a computer or other equipment.

• Barcode readers are mostly used in shopping malls.

• This device scans the barcodes present in the product labels to input the price of the products to the billing machine. It is very useful for quick billing.

Output Devices

• The system unit processes the input given to the computer and gives the output. This output can either be displayed on the monitor or printed on paper using a printer.

Monitor

• The monitor looks like a television screen.

• It is also called Visual Display Unit (VDU)

• It is used to display information from the computer.

• There are coloured as well as black and white monitors.

• The monitor displays text and graphics.

• Based on the technology used, monitor is classified into two types. They are,

– Cathode Ray Tube (CRT) monitors

– Liquid Crystal Display (LCD) monitors

Printer

• A printer is used for transferring data from the computer to the paper.

• There are colour printers as well as black and white printers.

• The different types of printers are Dot Matrix Printers, Inkjet Printer and Laser Printers

Dot matrix Printer

Inkjet Printer Laser Printer

Laser Printer

Types of Printers

Dot Matrix Printer	Inkjet Printer	Laser Printer
Prints characters in the form of dots	Prints fully formed characters	Prints fully formed characters
Speed: 200-540 characters per second	Speed: 4-8 pages per minute	Speed: 4-20 pages per minute
Not very expensive	Moderately priced	Expensive

Touch Screen

• A touch screen is a computer display screen that is sensitive to human touch.

• It allows the user to interact with the computer by touching pictures or words displayed on the screen.

• Touch screens are used to display the output information on the screen as well as to give input by touching the words or pictures on the screen. Thus it is an input/output device.

• Touch screens are normally used when information has to be accessed with minimum effort.

Computer Basics

2011-05-18T19:34:00.000-07:00

Computer Basics

• Define a computer

• Understand the use of computers in everyday life

• Identify the benefits and limitations of computers

• Understand the different generations of computers

• Identify the types of computer systems

• Identify the basic components of the computer

• Understand the working of a computer

• Know about input and output devices

• Understand the storage capacity of a computer

• Explain about the various storage media and disk drives

• Define software

• List the types of software

• List the different types of computer languages

• What is a Computer?

A computer can be defined as an electronic device that can accept store

and process data to produce the required result according to user direction .

Uses of a Computer

Computers are used in:

• Airline and Railway Reservations

• Medical Diagnosis

• Weather Forecasting

• Payment of telephone and electricity bills

• Banking

• Manufacturing products like automobiles, shoes, computer cabinets, etc.

• Cartoon Film Production

• Space Research

• Creation of blueprints for houses

• Benefits and Limitations of a Computer

• The various benefits of computers are:

• Speed –

Computers are very fast.

• Accuracy –

Computers are very accurate. If the input is right, they never make mistakes.

• Diligence –

Computers never get tired or bored of doing the same task continuously. They work in the same manner all the time.

• Storage –

A computer can store large amounts of information in its memory.

• Automation –

If a task has to be performed several times, the computer needs to be instructed only once and it automatically completes the task.

• The limitations of a computer are:

• It cannot perform any task on its own. We need to give the computer instructions on exactly what it has to do.

• If an unanticipated situation arises, computers will either produce wrong results or abandon the task all together. They do not have the potential to work out alternate solutions.

• Generations of Computers

The growth of a computer can be classified into five generations of Computers.

• First Generation

– The basic component of the first generation of computers was vacuum tubes. A vacuum tube is an electronic device that permitted the processing of digital signals at a faster speed.

• Second Generation

– The second generation of computers used a solid-state device called transistor in the place of vacuum tubes. Transistors were very convenient when compared to vacuum tubes. They were more efficient and cheaper than the vacuum tubes.

• Third Generation

– Though transistors were an improvement over the vacuum tube, they still had some limitations. They had complex circuits with numerous connections between the individual transistors.

– A major breakthrough was achieved when hundreds of transistors were successfully connected together and placed on a single silicon chip called the Integrated Circuit (IC). The use of IC chips in the place of transistors gave birth to third generation of computers.

• Fourth Generation

– LSI technology led to the development of Very Large Scale Integration (VLSI) where millions of transistors could be placed on a single chip called the Microprocessor. This was the basic component of fourth generation of computers. The VLSI chips could perform faster calculations

• Fifth Generation

– In this generation, researches are focused on developing “thinking computers”. This technology is referred to as Artificial Intelligence. These computers are called the fifth generation computers. The computers you are using now belong to the fifth generation of computers.

Types of Computers

• Based on the size, cost and performance, computers can classified into:

– Micro computers

– Mini computers

– Mainframes

– Super computers

• Micro Computers

• Microcomputers are also called as personal computers (PCs). These computers use microprocessors.

• They are small in size and they can perform difficult tasks.

• They are used mainly for desktop publishing, accounting, statistical analysis, graphics designing and project management.

• The classification of PCs is as follows:

– Desktops

– Portables

• Laptops

• Notebooks

• Palmtops

Mini Computers

• Minicomputers are small general-purpose computers. These computers can perform more complex tasks and cost more than microcomputers.

• They are larger in size and they have small to medium storage capacity.

• They are used for processing data and analysing results of experiments. They are also used for controlling and monitoring production processes.

• Some examples are PDP 11/42 and VAX 11.

Mainframe Computers

• Mainframes are more powerful than minicomputers.

• They have high processing speeds and can store large amounts of data. They are used in wide area networks and support hundreds of users. However, these computers consume more electricity.

• Some examples are IBM 3000 series and Univac 1180.

Super Computers

• Supercomputers are the largest and fastest computers. They are also the costliest computers.

• They are used in fields like science and defence. These computers are used for designing and launching missiles, weather forecasting, biomedical research, aircraft design and automobile design.

• There are only a few supercomputers throughout the world. India owns a series of supercomputers called PARAM developed by C-DAC.

Application Software Part-2

2011-05-17T02:12:00.000-07:00

• The key features of graphics and multimedia programs

• The key features of home, personal and educational programs

• The types of application software used in communications

• The different types of learning aids available for application software

• CAD

• Clip

• Authoring software

• Web application

• ASP

• WBT

• Online Help

• Web based Help

• Wizard

• What are some popular graphics and multimedia software products?

• What is Computer-Aided Design (CAD)?

• Software that allows you to create engineering, architectural and scientific designs

• What are paint / image editing software?

• Used to create and modify graphical images

• Sometimes called illustration software

• What is video and audio editing software ?

• Video editing software allows you to modify a segment of a video called a clip

• Audio editing software allows you to modify audio clips

• What is multimedia authoring software?

• Allows you to combine text, graphics, audio, video and animation into an interactive presentation

• What is Web page authoring software?

• Allows users of all skills levels to create Web pages

• Some application software programs include Web page authoring programs

• What software products are available for home, personal and educational use?

• What software facilitates communication?

• What is a Web application?

• A software application that exists on a Web site, such as maps and directions

• Some Web applications store your data and information at their site

• Some are free

• What is an application service provider (ASP)?

• What is Web-based training (WBT)?

• Self-directed, self-paced instruction on a topic on the Web

• Distance Learning (DL) is the delivery of education at one location while the learning takes place at other locations

• What is Online Help?

• Electronic equivalent of a user manual

• Context-sensitive help

• What is Web-based Help?

• A web site linked from Online Help

• Provides updates and more resources to respond to technical issues about a program

• Often has a Frequently Asked Questions (FAQ) page

• Some Web sites contain chat rooms where user can talk directly with a technical support person

• What is a wizard?

• An automated assistant that helps you complete a task

• How can I learn more about a software package?

• Books

• Web

• School

Application Software Part-1

2011-05-15T18:13:00.000-07:00

1. Identify the categories of application software

2. Explain ways software is distributed

3. Explain how to start and interact with application software

4. Identify the key features of widely used business programs

• What is Application software?

• List the four (4) categories of an application software

Packaged software
Custom software
Shareware
Freeware
Public-domain software
System software
Window
Dialog box
Word processing software
Voice recognition
Spreadsheet software
Database software
Presentation graphics
Note taking software
PDA software
Software suite
Project management
Accounting software
What is application software?

• Programs that perform specific tasks for users

• How is software distributed?

v Packaged software

v Custom software

v Shareware

§ distributed free for trial period

v Freeware

§ copyrighted software provided at no cost

v Public-domain software

§ freeware with no copyright restrictions

• What is system software?

• Programs that control the operations of the computer

• Serves as the interface between the user, the application software and the computer’s hardware

• How do you start an application?

• From the desktop, click the Start button, point to All programs and click the name of the application

• The program’s instructions load into memory

• What is a window?

• A rectangular area of the screen that displays a program, data and/or information

• What is a Dialog box?

• A special window that provides information, presents available options or requests a response

• What is Business software?

• Software that assists people in becoming more effective and efficient

• What is word processing software?

• Allows users to create and manipulate text and graphics

• Clip art is a collection of graphics that you can insert in documents

• What are popular word processing features?

• What is voice recognition?

• The computer’s capability of distinguishing spoken words

• What is spreadsheet software?

• Organizes data

• Performs calculations and recalculates when data changes

• What is Database software?

• What is presentation graphics software?

• Used to create visual aids for presentations

• A presentation is sometimes called a slide show

• What is note taking software?

• Enables users to enter typed text, handwritten comments, drawings or sketches anywhere on the page

• Notes are organized like a notebook

• What is PDA software?

• Allows PDA users to create documents, take notes, manage budgets, view photographs and more

• Most include Personal Information Manager (PIM) software

• Calendar, address book, synchronization with desktop computer

• What is a software suite?

• What is Project Management Software?

• Allows you to plan, schedule, track and analyze the events, resources and costs of a project

• What is Accounting software?

• Helps companies record and report their financial transactions

System Software Part-1

2011-05-15T01:41:00.000-07:00

• Device dependent

• Device independent

• Proprietary software

• Downward compatible

• Upward compatible

• Embedded OS

• Network OS

• Stand-alone OS

• Virus

• Anti-virus program

• Personal firewall

• File compression

• PC maintenance

• What are some characteristics of operating systems?

• What are three categories of operating systems?

• What is DOS (Disk Operating System)?

• How do Windows versions compare?

• What is Windows XP?

• Microsoft’s fastest, most reliable Windows operating system

• Available in five editions:

• Home Edition

• Professional Edition

• Tablet PC Edition

• Media Centre Edition

• 64-bit Edition

• What are some features of Windows XP?

• What is Mac OS X?

• Available only for computers manufactured by Apple

• Macintosh operating system has been model for most GUIs

• What is UNIX?

• Used by power users because of its flexibility and power

• Most versions offer GUI

• Both a stand-alone and a network operating system

• What is Linux?

• Popular, free, multitasking UNIX-type operating system

• Open-source software - code is available to public

• Both a stand-alone and a network operating system

• What are examples of network operating systems?

• What is an embedded operating system?

• Found on most mobile computers, PDAs and other small devices

• Windows CE.NET is scaled-down version of Windows

• What are two operating systems for PDAs?

• Windows Mobile 2003 for Pocket PC

• Palm OS for Palm, Visor and CLIE

• What is Symbian OS?

• Open-source, multitasking operating system designed for smart phones

• Make telephone calls, save appointments, browse Web, send and receive e-mail and faxes, and etc

• What is a virus?

• Potentially damaging computer program

• Affects computer without user’s knowledge

• What is an anti-virus program?

• Identifies and removes viruses in memory, storage media and incoming files

• Must be updated frequently

• What is a personal firewall?

• Protects personal computer from unauthorized intrusions

• Monitors all transmissions to and from computer

• What is a file compression utility?

• Shrinks size of files to free up room and improve performance

• Compressed files are sometimes called zipped files

• Two popular utilities : PKZIP and WinZip

• What is a personal computer maintenance utility?

• Identifies and fixes operating system problems and disk problems

• Some continuously monitor computer to identify problems before they occur

operating System Utility Programs

2011-05-13T21:27:00.000-07:00

Utility
File manager
Image viewer
Uninstaller
Disk scanner
Disk defragmenter
Diagnostic utility
Backup
Screen Saver

What is a utility program?
System software that performs maintenance-type tasks·
Also called utility

What is a file manager?

Performs functions such as copying, renaming, deleting and moving files
Image viewer displays contents of graphics file when you double click on it

• What is an uninstaller?

• What is a disk scanner?

• Detects and corrects problems on hard disk or floppy disk

• Searches for and removes unnecessary files

• What is a disk defragmenter?

• Reorganizes files and unused space on hard disk so programs run faster

• What is a diagnostic utility?

• Compiles technical information about hardware and some software

• Prepares report outlining problems

• What is a backup utility?

• Copies selected files or entire hard disk onto another disk or tape

• Most compress files during backup to require less storage space

• What is a screen saver?

• Causes monitor’s screen to display moving image or blank screen if there is no activity for a specified time

• To secure computer, user configures screen saver to require password to deactivate

Types of System Software

2011-05-11T09:06:00.000-07:00

Description about system software:-

• Operation system

• Plate form

• Cold Boot

• Warm Boot

• Boot Disk

• User Interface

• Command Line Interface

• Menu driven interface

• Graphical user interface

• Single User

• Multi User

• Multiprocessing

• Multi-User

• Fault-tolerant Computer

• Memory Management

• Spooling

• Device Driver

• What is system software?

• What is an operating system?

• Set of programs that coordinates all activities among computer hardware resources

• Sometimes called the platform

What is cross-platform application?

• Runs identically in multiple operating systems

• Operating system that computer uses is sometimes called the platform

• What is Booting?

• Process of starting or restarting a computer

• Cold boot

• Turning on computer that has been powered off

• Warm boot

• Restarting computer that is powered on

What messages display on the screen when you boot the computer ?

How does a personal computer boot up ?

Step. 1

Power supply sends signal to components in system unit

Step.2

Processor access BIOS to start computer

Step.3

BIOS runs Test normally called POST (Power on Self Test) , to check plugged components such as Mouse, OS, Keyboard , VGA card.

Step.4

Results of POST are compared with data in CMOS chip

Step.5

BIOS look for system files in floppy disk drive or CD/DVD drive, and then hard disk

Step.6.

Kernel (core) of operating system loads into RAM

Step.7

Operating system loads configuration information and displays desktop on screen

• What is a Recovery disk?

Contains system files that will start computer when computer cannot boot. So special recovery disk is used for resrore system files called also boot disk in computer system.

• Step 1.

Click Start button on taskbar, point to All Programs on Start menu, point to Accessories on All Programs submenu, point to Systems Tools on Accessories submenu, and then point
to Backup.

Step 2.

Click Backup on Systems Tools submenu to open the Backup Utility window. (If Backup or Restore Wizard displays, click Advanced Mode link.) Point to Automated System Recovery Wizard button.

Step 3.

Click Automated System Recovery Wizard button to create recovery disk. Follow the on-screen instructions and insert a diskette when prompted.

• What is a user interface?

• Controls how you enter data and instructions and how information displays on screen

• Command-Line interface (CLI)

• Menu-Driven interface

• What is a Graphical User Interface (GUI)?

• User interacts with menus and visual images such as icons and buttons

• What are single user / multitasking?

• Working on two or more programs that reside in memory at same time

• Foreground contains program you are using

• Background contains programs that are running but are not in use

• What are other program management features of operating systems?

• What is Memory management?

• Optimizing use of Random Access Memory (RAM)

• With virtual Memory (VM), portion of hard disk is allocated to function as RAM

• Step 1.

The operating system transfers the least recently used data and program instructions to disk because memory is needed for other functions.

• Step 2.

The operating system transfers data and program instructions from disk to memory when they are needed.

• How does an operating system schedule jobs ?

• What is spooling?

• Sending print jobs to buffer instead of directly to printer

• Print jobs line up in queue

• How do you install a device driver?

Step 1.

Open Control Panel window. Point to Printers and Other
Hardware link.

Step 2.

Click Printers and Other Hardware link. Point to Add a printer link.

Step 3.

Click Add a printer link. Follow on-screen instructions.

Step 4.

Add Printer Wizard searches for Plug and Play printers on your computer. If it finds any such printers, it installs them.

Step 5.

If Add Printer Wizard cannot find any Plug and Play printers, you can select type of printer you want to install. An on-screen prompt may ask you to insert floppy disk, CD-ROM or DVD-ROM that contains necessary driver files to complete the installation of printer.

• How do you establish an Internet connection?

• Windows XP includes New Connection Wizard

• Guides user through setting up connection between computer and Internet

• How does an operating system monitor performance?

• Provides program, called performance monitor, that accesses and reports information about system resources and devices

• What is a Network operating system?

• Allows users to share printer, Internet access, files and programs on a network

• Administers security by establishing user name and password for each user

Storage Device of Computer

2011-05-09T18:55:00.000-07:00

Types of computer Storage Devices

• Tape

• Backup

• Sequential access

• Direct access

• PC Card

• Miniature mobile storage media

• Card reader

• Smart card

• E-money

• Microfilm

• Microfiche

• What is Tape?

• Magnetically coated plastic ribbon capable of storing large amounts of data at low cost

• Primarily used for backup

• How is data stored on a tape?

• Sequential access
• Reads and writes data consecutively, like music tape
• Unlike Direct access – used on floppy disks, Zip disks, hard disks, CDs and DVDs – which can
locate particular item immediately

• What is a PC Card?

• Adds capabilities to computer

• Credit-card sized device commonly used in notebook computers

• What is miniature mobile storage media?

• Storage for small mobile devices

• What are common types of miniature mobile storage media?

• What is a card reader?

• Reads information stored on miniature mobile storage media

• Type of card determines type of card reader needed

• What is a smart card?

• Stores data on microprocessor embedded in small card

• Input, process, output and storage capabilities

• What are the types of smart cards?

• Intelligent smart card contains processors and has input, process, output and storage capabilities

• Memory card has only storage capabilities

• What is e-money (electronic money)?

• What are microfilm and microfiche?

• Stores microscopic images of documents on roll or sheet of film

• Images recorded using computer output microfilm recorder

How do life expectancies of various media compare

v Microfilm and microfiche have longest life of any storage media

What are recommended storage devices for the Home Users?

Internet hard drive

• What are recommended storage devices for the Small Office / Home Office (SOHO) users?

• What are recommended storage devices for the mobile users?

• What are recommended storage devices for the Large business users?

• What are recommended storage devices for the Power user?

Output Device of Computer

2011-05-09T00:41:00.000-07:00

• What is output?

• Data that has been processed into a useful form called information

• What is is an output device ?

• Any hardware component that can convey information to use

• What is a Display device?

• Output device that visually conveys information.Information on display device sometimes called softcopy. mnitor houses display device as separate peripheral

•

• What is a CRT monitor ?

• Contains Cathode-Ray Tube (CRT)

• Large sealed, glass screen

• Screen coated with tiny dots of phosphor material

• Pixel or picture element is single point in electronic image

• Three dots (red, blue and green) combine to make a pixel

• Common sizes are 15, 17, 19, 21 and 22 inches

• Viewable size is diagonal measurement of actual viewing area provided by the monitor

• What is Resolution?

• Describes the sharpness and clarity of image

• Higher resolution makes image sharper, displays more text on screen, makes some elements smaller

• Refresh rate is speed at which monitor redraws images on screen

• What is Dot pitch?

• Measure of the distance between pixels

• Sometimes called pixel pitch

• Smaller the distance between the pixels, the sharper the image

• What is Refresh Rate ?

• Speed at which monitor redraws images on the screen

• What is a video card?

• Converts digital output from computer into analogue video signal

• Controls how display device produces picture

• Also called graphics card or video adapter

• What is Bit depth?

• Number of bits a video card uses to store information about each pixel

• Also called colour depth

• Determines number of colours a video card can display Greater the number of
bits, better the resulting image

• What are Video standards ?

• Video Electronics Standards Association (VESA) develops video standards

• What are various video card configurations ?

• What is Electromagnetic radiation (EMR) ?

• Magnetic field that travels at speed of light

• Small amount produced by all CRT monitors

• LCD monitors do not pose this risk

• What is a Liquid crystal display (LCD) monitor?

• Uses liquid crystals between two sheets of material to present information on
screen

• Electric current passes through crystals, which creates images on the screen

• Takes up less desk space than CRT monitor

• Consumes less than one-third the power

• Where are some features of LCD screens?

• Lightweight and compact

• Consumes less than one-third of the power than does a CRT monitor

• Ideal for notebook and handheld computers

• What is a Printer ?

• Output device that produces text and graphics on paper

• Result is hard copy or printout

• Two orientations : Portrait and Landscape

• Types of printers :-

• Impact printers

• Non-impact printers

• What is an impact printer?

• Forms characters by striking a mechanism against ink ribbon that physically
contacts paper

• Ideal for printing multipart forms

• Can withstand dusty environments, vibrations and extreme temperatures

• Types of impact printers :

• Dot-matrix printer

• Line printer

• What is a Dot-matrix printer?

• Impact printer that produces printed images when tiny wire pins on print head
mechanism strike inked ribbon

• Impact printer forms characters by striking mechanism against inked ribbon
that contacts paper

• Most use continuous-form paper

• How does a Dot-matrix printer work?

• When ribbon presses against paper, it creates dots that form characters and
graphics

• A higher number of pins (9 to 24) means printer prints more dots per character,
which results in high

• What is a Line printer?

• High-speed impact printer that prints entire line at a time

• Speed measured in lines per minute (lpm) it can print

• Band printer prints fully formed characters using a hammer mechanism

• Shuttle-matrix printer is high-speed printer that works like dot-matrix printer

• What is a Non-impact printer?

• Forms characters and graphics on piece of paper without actually striking
paper.

• Types of non-impact printers :

• Ink-Jet printer

• Laser printer

• Thermal printer

• What is an Ink-jet printer?

• A type of non-impact printer that sprays tiny drops of liquid ink onto paper

• Non-impact printer forms characters and graphics without striking paper

• Prints in black-and-white or colour on a variety of paper types.

• What is the Resolution of printer?

• Sharpness and clarity

• Measured by number of dots per inch (dpi) printer can output

• What is a Laser printer?

• High-speed, high-quality non-impact printer

• Prints text and graphics in very high-quality resolution, ranging from 600 to
2,400 DPI (Dots Per Inch).

• Typically costs more than ink-jet printer, but is much faster

• What is a Thermal printer?

• Generally images by pushing electrically heated pins against heat-sensitive paper

• Dye-sublimation printer, also called a digital photo printer

• Uses heat to transfer dye to specially coated paper

• What is a Mobile printer?

• Small, lightweight, battery-powered printer that allows mobile user to print from
notebook computer, Tablet PC or PDA while traveling

• What is a Label printer?

o Small printer that prints on adhesive-type material

o Most also print bar codes

o Postage printer has built-in digital scale and prints postage stamps

Ø What is a Plotter?

o Sophisticated printer used to produce high-quality drawings

o Large-format printer creates photo-realistic-quality colour prints

• What is wireless printing?

• Output transmitted to printer wirelessly via infrared light waves or radio waves

• Bluetooth printing uses radio waves

• Devices need to be within 30-foot range

• What is an Audio output device?

• Computer component that produces music, speech or other sound

• Speakers and headsets are common devices

• What is voice output?

• Computer talks to you through speakers on computer

• What is Internet telephony?

• Allows you to have conversation over Web, just as if you were talking on the
telephone

• What is a facsimile (fax) machine?

• Device that transmits and receives documents over telephone lines

• What is a Multifunction peripheral?

• Provides functionality of printer, scanner, copy machine and fax machine.

• What is a Data projector?

• Device that takes image from computer screen and projects it onto larger
screen.

• What is a Point of Sale (POS) terminal?

• Records purchases, processes credit or debit cards, and updates inventory

• Swipe credit or debit card through card reader, which reads customer’s personal data
from magnetic strip

• Output from POS terminals serves as input to host computer

• What is an Automatic Teller Machine (ATM)?

• Self-service banking machine that connects to host computer through network

Input Device of Computer

2011-05-07T13:00:00.000-07:00

What is peripheral?

v Devices that connects to a system unit and is controlled by the Central Processing Unit (CPU) in the computer

• What is input ?

• Any data or instructions entered into memory of computer

What are the two types of input?

v Data

Ø Unprocessed text, numbers, images, audio and video

v Instructions

Ø Programs

Ø Commands

Ø User responses

• What are input devices ?

• Input devices is any hardware component that allows an user to enter data or instructions into a computer

The categories of input devices:

• The keyboard

• Pointing devices

• Scanners and Reading devices

• Input devices for the physically challenged users

• What is a keyboard?

• An input device that contains keys, users press to enter data into a computer system.keyboard Converts letters, numbers and other characters into electronic signals that are machine-readable.

It is a 8-bit code (ASCII-8) or able to accommodate 256 different

Characters.

• Desktop computer typically have from 101 to 105 keys

• Required by software with Command Line Interface (CLI)

• How is the keyboard divided?

• Typing area

• Numeric keypad

• Function keys, special keys that issue command

The types of keyboards:

v QWERTY

v DVORAK

v Enhanced keyboard

v Wireless keyboard

v Portable keyboard

v Laptop keyboard

v Handheld keyboard

v Ergonomic keyboard

v Virtual keyboard

v QWERTY keyboard

v The most widely used type of keyboard, so named because the first letters on the top alphabetic line spell QWERTY

v DVORAK keyboard

v A type of keyboard that places frequently types letters in the middle of the typing area

Enhanced keyboard

v A keyboard that has 12 function keys along the top : 2 Control (CTRL) keys and 2 Alternate (ALT) keys along the bottom and a set of arrow keys and other additional keys between the typing area and the numeric keypad

Wireless or Cordless keyboard

v Battery-powered keyboard that transmits data using wireless technology, such as radio waves or infrared light waves

• Portable keyboard

• A full sized keyboard, that an end-user conveniently can attach or remove from a handheld computer or PDA

• Laptop and Handheld keyboard

• Notebook and many handheld computers have built-in keyboards

Ergonomics keyboard

v Design to minimise strain on hands or wrists

v Ergonomics incorporates comfort, efficiency and safety into design of items of workplace

• Virtual keyboard.

Projects infrared image of keyboard onto any flat surface

• What is a pointing device?

v An input device that allows the user to control a pointer on the display screen

v Required by software with Graphical User Interface (GUI)

• The types of pointing devices

• Mouse

• Trackball

• Touchpad

• Pointing stick

• Joystick and Wheel

• Light pen

• Touch screen

• Stylus or Digital pen

• What is a Mouse ?

• Pointing device that fits under palm of hand

• Pointing device controls movement of pointer, also called mouse pointer

• A pointer on screen takes several shapes

The types of pointing devices :

• Mechanical mouse

• Optical mouse

• Cordless mouse

• How does a mechanical mouse work ?

• Rubber or metal ball is on its underside

• Movement of mouse translates into signals that computer understand

• How does an optical mouse work ?

• Senses light to detect mouse’s movement

• More precise than mechanical mouse

• Connect using a cable or wireless

• Wireless or Cordless mouse

• What is a trackball ?

• Stationary pointing device with a ball on its top

• To move pointer, rotate ball with thumb, fingers or palm of hand.

What is a Touch pad?

• Touch pad is small, flat, rectangular pointing device that is sensitive to pressure and motion. It Often used in laptop computers.

• What is a pointing stick?

• Pointing stick is pointing device shaped like pencil eraser positioned between keys on keyboard

• Moves pointer as pressure is applied

• Often used in laptop computers

• What are a joystick and a wheel?

• Joystick

• Is vertical lever mounted on a base

• It enables the user to move within the screen’s environment

• Widely used in computer games industry

• Wheel

• Wheel is steering-wheel-type input device

• Users turn the wheel to simulate driving a car, truck etc.

• Most wheels also include foot pedals to simulate car brakes and accelerator

• What is a light pen?

• Handheld input device that can detect light

• Press light pen against screen surface and then press button on pen

• What is a Touch screen ?

• Monitor has a touch-sensitive panel

• Touch areas of screen with finger

• Used to issue simple commands or choose from a list of options

• Often used with kiosk

• What is a stylus or digital pen ?

• Looks like a ballpoint pen, but uses pressure to write text and draw lines

• Used with graphics tablets, flat electronic boards and handheld computers

• What is an Electronic signature ?

• Is a legal signature created using special software, stylus and graphics tablet

• Also called as e-signature

• What is a scanner ?

• Light-sensing device that captures data directly from source document

• Source document is original form of data (printed text or graphics)

• Used for image processing, converting paper documents into electronic images

• What is an optical reader?

• Device that uses light source to read characters, marks and codes and then converts them into digital data

• What is an OCR font?

• OCR device determines characters’ shapes by detecting patterns of light and dark

• OCR software converts shapes into characters the computer can understand

• What is a turnaround document?

• It is a document that after being output by the computer can be used to record data and this data can then be input to the computer using a document reader

• Portion you return has information printed in OCR characters

• What is an Optical Mark Recognition (OMR) ?

• Reads hand-drawn pencil marks such as small circles or rectangles

• Used for ballots, enrollment application, attendance, questionnaires, course evaluation and multiple choice tests and examination

• What is a Bar code?

• Identification code that consists of a set of vertical lines and spaces of different widths

• The symbol of the Universal Product Code (UPC)

What is a Bar code scanner?

v Uses laser beam to read bar codes

What is a Magnetic-Ink Character Recognition (MICR) reader?

v Can read text printed with magnetized ink

v Banking industry almost exclusively uses MICR for cheque processing

• What is Biometrics?

• Authenticates person’s identity by verifying personal characteristic

• Fingerprint scanner captures curves and indentations of fingerprint

• Hand geometry system measures shape and size of person’s hand

• What are examples of Biometric technology?

• Voice verification system compares live speech with stored voice pattern

• Signature verification system recognizes shape of signature

• Iris recognition system reads patterns in blood vessels in back of eye

• Biometric data is sometimes stored on smart card, which stores personal data on

microprocessor embedded in card.

computer component

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The component in the system unit.

• Ports and connectors

• Buses

• Bay

• Power supply

• What are ports and connectors?

• Port connects external devices to system unit

• Connector joins cable to peripheral

• Available in one of two genders : Male and Female

What is a serial port ?

v Transmits one bit of data at a time

v Connects slow-speed devices, such as mouse, keyboard and mode

• What is a parallel port?

• Connects devices that can transfer more than one bit at a time, such as a print

What are USB port ?

v USB (Universal Serial Bus) port can connect up to 127 different peripherals together with a single connector type

v PCs typically have two to four USB ports on front or back of the system unit

v Single USB port can be used to attach multiple peripherals in a daisy chain

Ø First USB device connects to USB port on computer

Ø Second USB device connects to first USB device

Ø Third USB device connects to second USB device, and so on

What are special-purpose ports?

v Allow users to attach specialized peripherals (digital video cameras, colour printers, scanners and disk drives) or transmit data to wireless devices

Ø FireWire port

Ø MIDI (Musical Instrumental Digital Interface) port

Ø SCSI (Small Computer System Interface) port

Ø IrDA (Infrared Data Association) port

Ø BluetoothTM port

What is a bus?

v Channel that allows devices inside computer to communicate with each other

Ø System bus connects processor and RAM

Ø Bus width determines number of bits transmitted at one time

Ø Word size is the number of bits processor can interpret and execute at a given time

What is an expansion bus?

Allows processor to communicate with peripherals

• What is a bay?

• Open area inside system unit used to install additional equipment

• Drive bays typically hold disk drives

What is power supply?

v Converts Alternating Current (AC) to Direct Current (DC)

v Some peripheral devices have AC adapter

v Requires a fan to cool off the heat generated by the CPU and other electronic components