Computer Engineers

Differences Between HTML and XHTML

2012-01-23T11:57:00.000-08:00

Even though this is a CSS reference, we should spend some time talking about HTML and XHTML, because your choice of markup language will affect how CSS is applied in some instances. Moreover, in order to understand the variations in the way CSS is applied to HTML and XHTML, you need to grasp the fundamental differences between the two markup languages.
The most important difference between the two markup languages is thatHyperText Markup Language, or HTML, is an application of SGML (Standard Generalized Markup Language), and allows an author to omit certain tags and use attribute minimization

The Extensible Hyper Text Markup Language, or XHTML, is an application of XML (Extensible Markup Language).

It doesn't permit the omission of any tags or the use of attribute minimization. However, it provides a shorthand notation for empty elements—for example, we could use <br/> instead of <br></br>—which HTML does not. A conforming XML document must be well formed, which, among other things, means that there must be an end tag for every start tag, and that nested tags must be closed in the right order.

When an XML parser encounters an error relating to the document’s well-formlessness, it must abort, whereas an HTML parser is expected to attempt to recover and continue.

difference between HTML and XML

2012-01-23T11:54:00.000-08:00

HTML is an abbreviation for Hyper Text Markup Language while XML stands for eXtensible Markup Language.The differences are as follows:-
HTML was designed to display data with focus on how data looks while XML was designed to be a software and hardware independent tool used to transport and store data, with focus on what data is.
HTML is a Markup language itself while XML provides a framework for defining markup languages.
HTML is a presentation language while XML is neither a programming language nor a presentation language.
HTML is case insensitive while XML is case sensitive.
HTML is used for designing a web-page to be rendered on the client side while XML is used basically to transport data between the application and the database.
HTML has it own predefined tags while what makes XML flexible is that custom tags can be defined and the tags are invented by the author of the XML document.
HTML is not strict if the user does not use the closing tags but XML makes it mandatory for the user the close each tag that has been used.
HTML does not preserve white space while XML does.

Difference between a counter and a register

2012-01-23T11:48:00.000-08:00

A register can hold data, and it can be used for temporary storage or, in the case of an accumulator, it can participate in arithmetic or logical operations.
A counter is a special case of a register. Usually, it can only be loaded, stored, or incremented, or used for the stack or as the program counter.

A register can hold data, and it can be used for temporary storage or, in the case of an accumulator, it can participate in arithmetic or logical operations.
register has the same clock
A counter is a special case of a register. Usually, it can only be loaded, stored, or incremented, or used for the stack or as the program counter. counter do not need to have the same clock.

difference between register and memory

2012-01-23T11:44:00.000-08:00

Registers are storage locations internal the the processor. CPU instructions operate on these values directly. On RISC processors, all data must be moved into a register before it can be operated. On CISC (Intel) chips, there are a few operations that can load data from RAM, process it, and save the result back out, but the fastest operations work directly with registers. Also, there are registers that are set aside for certain tasks, these generally include a program counter, stack, and flags.

Each register also has a size that determines the maximum amount of data that can be processed at a time. The registers on Pentium chips, for example, are 32 bits.

Finally, there are generally only a few registers available on a processor. Intel chips, for example, have 6 general purpose registers, and several specialized registers including a base register, stack register, flags register, program counter, and some addressing registers.

Memory, or RAM, is located external to the CPU. Generally speaking, data has to be loaded into a CPU register from memory before the CPU can process it, RAM is much slower than registers, there is a lot more RAM than registers, and generally memory can be addressed on a byte boundaries, where registers may not be able to access all the bytes in a register.

Difference between a compiler and an interpreter

2012-01-23T11:40:00.000-08:00

A compiler translates code from a source language to a target language, which can then be executed by a machine.
An interpreter reads code in an interpreted language (e.g. PHP, Perl, JavaScript) and directly executes the contained instructions.
Difference between compilation and interpretation

Without giving the definition for both words,A compilation is several things from A specific origin grouped together. and A iterpretation is making A opinion based judgement from the evidence on hand.

difference between java and javascript

2012-01-23T11:28:00.000-08:00

Java and JavaScript difference is that Java can stand on its own while JavaScript must be placed inside an HTML document to function. Java is a much larger and more complicated language that creates "standalone" applications. A Java "applet" (so-called because it is a little application) is a fully contained program. JavaScript is text that is fed into a browser that can interpret it and then it is enacted by the browser--although today's web apps are starting to blur the line between traditional desktop applications and those which are created using the traditional web technologies: JavaScript, HTML and CSS.
Another major difference is how the language is presented to the end user (that's you when you're surfing). Java must be compiled into what is known as a "machine language" before it can be run on the Web. Basically what happens is after the programmer writes the Java program and checks it for errors, he or she hands the text over to another computer program that changes the text code into a smaller language. That smaller language is formatted so that it is seen by the computer as a set program with definite beginning and ending points. Nothing can be added to it and nothing can be subtracted without destroying the program.
JavaScript is text-based. You write it to an HTML document and it is run through a browser. You can alter it after it runs and run it again and again. Once the Java is compiled, it is set. Sure, you can go back to the original text and alter it, but then you need to compile again.

Difference between LAN and WAN

2012-01-23T11:22:00.000-08:00

The other difference between LAN and WAN, is the speed of the network. The maximum speed of a LAN can be 1000 megabits per second, while the speed of a WAN can go up to 150 megabits per second. This means the speed of a WAN, is one-tenth of the speed of a LAN. A WAN is usually slower because it has lower bandwidth.

Computers in a LAN can share a printer, if they are all in the same LAN. On the other hand, a WAN cannot share a printer, so a computer in one country cannot use a printer in another country. A LAN does not need a dedicated computer to direct traffic to and from the Internet, unlike a WAN that needs a special-purpose computer, whose only purpose is to send and receive data from the Internet.

Another LAN vs. WAN comparison is the cost of the network. A WAN is more expensive than a LAN. It is easier to expand a LAN than a WAN. The equipment needed for a LAN is a network interface card (NIC), a switch and a hub. On the other hand, the equipment needed to connect a WAN to the Internet is a modem and a router. The modem may be a cable modem or a DSL modem that is connected to a wall jack, while the router should be configured so that it can handle the packets traveling between the WAN and the Internet.

A LAN uses the Ethernet standard, while a WAN uses the T1 standard.

Difference between Ram and Rom

2012-01-23T11:18:00.000-08:00

RAM is Random Access Memory, while ROM stands for Read Only Memory.
RAM is volatile and is erased when the computer is switched off. ROM is non-volatile and generally cannot be written to.
RAM is used for both read and write while ROM is used only for reading.
RAM needs electricity to flow to retain information while ROM is permanent.
RAM is analogous to a blackboard on which information can be written with a chalk and erased any number of times, while ROM is permanent and can only be read. One example is BIOS (basic input output system) that runs when computer is switched on and it prepares disk drives and processor to load OS from disk.

Difference between Data and Information

2012-01-23T11:14:00.000-08:00

Data is the collection of raw facts collected from any specific environment for a specific purpose. Data in itself does not show anything about its environment, so to get desired types of results from the data we transform it into information by applying certain processing on it. Once we have processed data using different methods data is converted into meaningful form and that form of the Data is called information If we consider the data in the above figure without the titles or the labels associated with the data (EmpName, age, salary) then it is not much useful. However, after attaching these labels it brings some meanings to us, this meaningfulness is further increased when we associate some other labels, like the company name and the department name etc. So this is a very simple example of processing that we can do on the data to make it information.
Once we have clear idea of what data and information is we proceed with another term knows as “schema” Schema is a repository or structure to express the format and other different information about data and database, as we can see from the database definition
“Database is a self describing collection of interrelated records.” The word self describing means that the data storage and retrieval mechanism and its format is described in the database, Actual place where these definitions and descriptions are performed is database schema.

Difference between electrical and electronics

2012-01-23T11:10:00.000-08:00

When we discuss them with respect to the type of signal, we can say "electrical" instruments deal with 'Analog' signals mostly defined by the equations of classical physics. They certainly obey Ohm's Law. Term 'Electrical' is associated with the typical conception of Electric Field(E) which exerts electric Force(F) on a charge particle(q) and it produces electricity, Where

F=qE

But 'Electronic' instruments are made to deal with 'Digital' signals. Analog electrical signal is changed to Digital signals ( 0, 1). They are semiconductors devices which never obey Ohm's Law and implemented with logic gates.

DIFFERENCE BETWEEN MEMORY AND STORAGE

2012-01-23T11:08:00.000-08:00

People often confuse the terms memory and storage, especially when describing the amount they have of each. The term memory refers to the amount of RAM installed in the computer, whereas the term storage refers to the capacity of the computer’s hard disk. To clarify this common mix-up, it helps to compare your computer to an office that contains a desk and a file cabinet.
The file cabinet represents the computer's hard disk, which provides storage for all the files and information you need in your office. When you come in to work, you take out the files you need from storage and put them on your desk for easy access while you work on them. The desk is like memory in the computer: it holds the information and data you need to have handy while you're working.
Consider the desk-and-file-cabinet metaphor for a moment. Imagine what it would be like if every time you wanted to look at a document or folder you had to retrieve it from the file drawer. It would slow you down tremendously, not to mention drive you crazy. With adequate desk space – our metaphor for memory – you can lay out the documents in use and retrieve information from them immediately, often with just a glance.
Here’s another important difference between memory and storage: the information stored on a hard disk remains intact even when the computer is turned off. However, any data held in memory is lost when the computer is turned off. In our desk space metaphor, it’s as though any files left on the desk at closing time will be thrown away.

Difference Between DOS and UNIX

2012-01-23T11:05:00.000-08:00

In today’s modern computing world, seeing a text-based interface can be quite daunting. Many people can’t even tell one from the other. DOS and UNIX are two operating systems that are predominantly text based. Although they might look similar, there are a lot of differences between them. Let’s start off with the GUI. DOS doesn’t have its own GUI so you are restricted to the command line. In contrast, UNIX can have a GUI just like most Linux variants. Most people who have UNIX setups forego the GUI to maximize performance.
The primary advantage of UNIX over DOS is its security. Although it greatly adds to the complexity of the operating system, it is essential for an operating system that is mainly used as a server. DOS was meant to be an operating system for personal computers and sacrificed security to make it easier to use.
There are a couple of usage differences between DOS and UNIX. The first difference is the case sensitivity of UNIX but not DOS. So in UNIX, the files example.exa and Example.exa can exist in the same folder but not in DOS. As long as the filename has the same characters, they would be considered as identical by DOS. The second, and less consequential of the two, is the use of slashes. DOS uses backslashes (\) to separate directories. In contrast, UNIX uses forward slashes (/) in its directory structure. These are just things to remember if you are familiar with one or the other.
The differences between UNIX and DOS are largely attributed to what they were meant to do. Nowadays, UNIX is still used with servers due to its light and performance-oriented nature. Only a handful of people have the ability to work with it. Although DOS was initially meant for personal computers, it has been replaced by more intuitive and easier-to-use operating systems like Windows, OS X, and even Linux. The only niche where DOS is still used is in embedded systems largely due to its very minimal requirements.

LCD vs LED Televisions

2012-01-23T11:02:00.000-08:00

The LCD television is a flat-panel television which utilizes a Liquid Crystal Display technology. It has two layers of glass which are polarized and stuck together. The liquid crystals are held in one of the layers. These liquid crystals pass, or block the light, to produce images on the screen when the electric current passes through it.
However, the crystals do not produce their own light. The light comes from the series of fluorescent lamps at the back of the screen. There are millions of shutters arranged in a grid, which open and close to release and trap some of the light that is not needed to create images. Then each shutter is paired with a colored filter which produces a sub-pixel. These are so small, that when they combine, they create a single pixel, which appears to be a single spot of color on the screen. With the help of the fluorescent lamps, the images created by the liquid crystals become visible to the viewer.
LCD television produces high image quality. They can be made very thin, which makes them less space-consuming, and the user can hang them anywhere. This makes them appealing to buyers.
LED TV’s are actually very much like LCD TV’s. They also have a flat-screen which utilizes Liquid Crystal Display technology. The only difference is their source of light, which is at the back of the screen. The LCD TV uses fluorescent lamps, and the LED TV uses LED (Light Emitting Diodes).
There are two types of LED backlighting. One is referred to as Edge lighting, and the other is called Full-Array lighting. With the Edge lighting, the series of diodes are arranged along the outside edges of the screen. When there is power, the light is distributed across the screen. Alternatively, in Full-Array lighting, there are several rows of diodes behind the entire surface of the screen. They provide more control over brightness and dimming, because the diodes can be turned on and off independently.
LED TV’s are LCD TV’s with a new backlight system. They are newly developed for LCD’s, because Light Emitting Diodes are said to give more balance in color saturation, and use less power than the fluorescent lamps. LED TV’s are the newest version, and that’s why they are currently more expensive than the standard LCD TV’s.
Summary:
LED TV’s are still LCD TV’s. They are just considered to be the newer LCD TV version because of the new backlight system used. The LED TV uses Light Emitting Diodes, while the standard LCD TV uses fluorescent lamps. Although they both still use Liquid Crystal Display technology. The main difference is the part behind their screen, which is the backlight.

Difference Between Laptop and Notebook

2012-01-23T10:50:00.000-08:00

When one sits to compare a notebook and a laptop they are bound to think about the difference between laptop and notebook as they both look similar and have similar traits and can be carried from one place to another easily. There are some differences between the two and it is important for a user to understand them.
When one wants to understand the difference between laptop and notebook they need to look at both the systems carefully as this will help them understand the difference between the two. Looking a notebook one will realize that this system is good for the users who are always on the go and need to work. Besides work these people can also use the system for purpose of entertainment also. The notebooks can be very expensive and are no model is cheap.
The notebooks are not heavy and are extremely light in weight and thus can be carried easily from one place to the other. One should always look for a notebook which is light in weight as this will increase its functionality. The notebooks are thin also and have a low profile. One cannot play DVDs and CDs in notebooks and they also do not have an internal floppy disk. The graphic subsystem of the notebooks is also minimal. The modem on these notebooks is integrated with the system and one can use network connections if they need to connect to the internet. Usually the screen of a notebook varies between 12” to 14”and it has a small keyword which is functional.
Having discussed the main features of a notebook, we can now talk about the difference between laptop and notebook. Laptop when compared to the notebook is bigger in size. One can easily work on the laptop and can place them on their lap when working and this is what the name of the same also suggests. There are several features in a laptop and it is a very powerful system especially when compared to a notebook. The basic difference between laptop and notebook is that of the weight. A laptop is always heavier than a notebook and they are also bigger in size. They have a graphic subsystem unlike the notebook and they also have an internal DVD-RW drive which is absent in a notebook. If one needs to use a CD or a DVD in a notebook they are required to attach an external CD Rom drive using a cable. Apart from this they have an integrated modem and Wi-Fi and network capabilities. The speakers in the laptops are integrated with the system and are of very high quality. These also have a battery life of nearly 2 hours whereas a notebook has a battery life of around 4-5 hours.
Another difference between laptop and notebook that one will notice is that of the keyboard as the keyboard of a laptop is bigger and is easier to use for the user. The screen of a laptop ranges from 14” to 17” and one can always choose the one that they are more comfortable using. The laptops are easily upgradeable which not the case with the notebooks is.
When one will compare the features of notebook vs laptop they will realize that a notebook is different from a laptop though they both might look similar. The notebooks are more portable and also have reasonable power. On the other hand it will not be wrong to say that laptops are kind of a replacement of a desktop computer and the difference between a desktop and a laptop is that of portability. The desktop is not portable whereas a laptop is though they both have quite the same features.
When one looks at a laptop and a notebook they might think they are similar but as per the above discussion there is a difference between laptop and notebook and this comes from the size and the features of both the systems. Both are suited to be used by the user who works on the move but the difference between the two comes from the functions and the use of both the systems. The choice will always depend on the use of the user.