ABOUT COMPUTER

Computer  

Is an electronic device used in almost every field even where it is most unexpected. It is made up of two things one is the hardware and other is software. All physical components of computer like keyboard, mouse, monitor etc comes under the hardware whereas all the programs and languages used by the computer are called software. These days computers are the tools for not only engineers and scientists but also they are being used by millions of people around the world.

Things are changing rapidly as the world is progressing. In this modern world people are using advanced machines to do their work. Computer is the most advanced machine that people use to do their work. This particular machine is used in every field of life. Advanced techniques are used with help of computers to diagnose dangerous diseases. Advanced manufacturing techniques are used with the help of computers to manufacture the products. Computers are extensively used in the field of engineering.

In past one machine was used to perform only a single task but now-a-days with the help of computers you can perform different tasks at one time. In modern business environment computers have special importance. A huge amount of time is saved due to multitasking. In business terms time is money, so if you are saving time you are saving money as well. Due to multitasking the costs of businesses have reduced.

Computers have become an integral part of our lives. Be it the desktop computers or laptop computers, both have various advantages in our daily life. The landscape of global communication has changed since computers have been introduced in our society. Importance of computers can be attributed to the fact that almost every sphere of our life is affected by computers. Information technology (IT) is a whole new industry that has developed after the introduction of computers. 

Computers are extremely important in the modern world of today. In the fast moving life of the modern world of today, computers hold tremendous significance. Computer has become an important tool for keeping databases, filing systems, track records. It has made record keeping and account keeping much much easier than it ever was. It helps an organization save tons of times. It has made data analysis extremely easy, and it can be done at a single click of the mouse.

What is the meaning of multitasking? It means that running several programs simultaneously. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. Multitasking may slow down a computer that is running several programs at one time.

Many advanced computers are designed to share their work across many CPUs. This process is called multiprocessing. This technique is generally used in powerful computers such as super computers, mainframe computers and serves.

There is no doubt that education and the learning process has changed since the introduction of computers: The search for information has become easier and amusing, and connectivity has expedited the data availability. Though experts systems have made computers more intelligent, they have not yet become a substitute of the human interaction in the learning process.

In an age of booming technology, running a business without computers is like trying to breathe without lungs. Like it or not, technology has become an integral part of the way business is done. Even if you perform services or provide products which are not technology related in and of themselves -- such as dry cleaning and hairstyling -- you may find that without a computer, it's difficult to place orders with suppliers or pass information to your accountant.

Thus, the entire world is fully dependent on computers. Due to this factor demand of computers has been increased.

HARDWARE & SOFTWARE

Computer - Hardware

Hardware represents the physical and tangible components of the computer,i.e., the components that can be seen and touched.

Examples of Hardware are following:

ü Input devices -- keyboard, mouse, etc.

ü Output devices -- printer, monitor, etc.

ü Secondary storage devices -- Hard disk, CD, DVD, etc.

ü Internal components -- CPU, motherboard, RAM, etc.

Relationship between Hardware and Software

ü Mutually dependent. Both of them must work together to make computer produce a useful output.

ü Software cannot be utilized without supporting hardware.

ü Hardware without set of programs to operate upon cannot be utilized and is useless.

ü To get a particular job done on the computer, relevant software should be loaded into the hardware.

ü Hardware is a one time expense.

ü Software development is very expensive and is a continuing expense.

ü Different softwares can be loaded on a hardware to run different jobs.

ü A software acts as an interface between the user and the hardware.

ü If hardware is the 'heart' of a computer system, then software is its 'soul'. Both are complimentary to each other.

Computer - Software

Software is a set of programs, which are designed to perform a well-defined function. A program is a sequence of instructions written to solve a particular problem.

 There are two types of softwares:

 ü System Software 

    ü Application Software

    

     

System Software

The system software is a collection of programs designed to operate, control and extend the processing capabilities of the computer itself. System software are generally prepared by computer manufacturers.
These softwares comprise of programs written in low level languages which interact with the hardware at a very basic level. System software serves as the interface between hardware and the end users.
Some examples of system software are Operating System, Compilers, Interpreter, Assemblers, etc.

Features of System Software are the following:

ü Fast in speed.

ü Difficult to design.

ü Difficult to understand.

ü Less interactive.

ü Smaller in size.

ü Difficult to manipulate.

ü Generally written in low-level language.

ü Close to system.

Application Software

Application softwares are the softwares that are designed to satisfy a particular need of a particular environment. All softwares prepared by us in the computer lab can come under the category of Application Software.
Application software may consist of a single program, such as a Microsoft's notepad for writing and editing simple text. It may also consist of a collection of programs, often called a software package, which work together to accomplish a task, such as a spreadsheet package.

Examples of Application softwares are the following:

ü Payroll Software

ü Student Record Software

ü Inventory Management Software

ü Income Tax Software

ü Railways Reservation Software

ü Microsoft Office Suite Software

ü Microsoft Word

ü Microsoft Excel

ü Microsoft Powerpoint

Features of Application Software are the following:

•  It is close to user.
•  It is easy to design.
•  More interactive.
•  Slow in speed.
• Generally written in high-level language.
•  Easy to understand.
•  Easy to manipulate and use.
•  Bigger in size and requires large storage space.

PARTS OF THE COMPUTER AND THEIR FUNCTIONS

 Ø Monitor: 
A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures. 

 Ø CPU: 
The central processing unit (CPU), or microprocessor, which acts as the "brain" of your computer. Another component is random access memory (RAM), which temporarily stores information that the CPU uses while the computer is on. The information stored in RAM is erased when the computer is turned off. 
Almost every other part of your computer connects to the system unit using cables. The cables plug into specific ports (openings), typically on the back of the system unit. Hardware that is not part of the system unit is sometimes called a peripheral device or device.

 Ø Keyboard:
A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys:

   

 v The function keys, found on the top row, perform different functions depending on where they are used.

  v The numeric keypad, located on the right side of most keyboards, allows you to enter numbers quickly.

   v The navigation keys, such as the arrow keys, allow you to move your position within a document or webpage.

   v You can also use your keyboard to perform many of the same tasks you can perform with a mouse.

 Ø Harddisk: 
Your computer's hard disk drive stores information on a hard disk, a rigid platter or stack of platters with a magnetic surface. Because hard disks can hold massive amounts of information, they usually serve as your computer's primary means of storage, holding almost all of your programs and files. The hard disk drive is normally located inside the system unit. 

 Ø Mouse: 
A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It's small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless. A mouse usually has two buttons: a primary button (usually the left button) and a secondary button. Many mice also have a wheel between the two buttons, which allows you to scroll smoothly through screens of information. When you move the mouse with your hand, a pointer on your screen moves in the same direction. (The pointer's appearance might change depending on where it's positioned on your screen.) When you want to select an item, you point to the item and then click (press and release) the primary button. Pointing and clicking with your mouse is the main way to interact with your computer. 

 Ø Printer: 
A printer transfers data from a computer onto paper. You don't need a printer to use your computer, but having one allows you to print e‑mail, cards, invitations, announcements, and other materials. Many people also like being able to print their own photos at home. 

    

     There are two types of printers:

v Impact Printers

v Non-Impact Printers

     Impact Printers

     The printers that print the characters by striking against the ribbon and onto the paper, are called impact printers.

     Characteristics of Impact Printers are the following:

Ø Very low consumable costs

Ø Impact printers are very noisy

Ø Useful for bulk printing due to low cost

Ø There is physical contact with the paper to produce an image

     

 Ø Speakers: 
Speakers are used to play sound. They may be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer. 

 Ø Modem: 
To connect your computer to the Internet, you need a modem. A modem is a device that sends and receives computer information over a telephone line or high-speed cable. Modems are sometimes built into the system unit, but higher-speed modems are usually separate components. 

 Ø Floppy Disk Drive: 
Floppy disk drives store information on floppy disks, also called floppies or diskettes. Compared to CDs and DVDs, floppy disks can store only a small amount of data. They also retrieve information more slowly and are more prone to damage. For these reasons, floppy disk drives are less popular than they used to be, although some computers still include them.

GLOSSARY FROM " A "

Ø 32-bit/16-bit: 
There are many advantages that 32 bit has over the 16 bit applications. 32 bit application have their own address space which creates a stable environment for a computer system. Whereas the 16 bit version runs in a shared address space which means if you experience a 16 bit application crash, it can crash the entire system. In addition, 32 bit runs much faster, it can handle multitasking and can handle much longer filenames than can the 16 bit application.
 

Ø Absolute Address:
The exact memory location of data or a specific location within a device.
 

Ø Absolute Reference:
A formulated cell reference that will not adjust when used to calculate the sum of specific cells. Most commonly used in spreadsheet applications.
 

Ø Access Point:
A networking connection device that is also known as the base station. This is a wireless hardware connection device that connects to a wired network to create wireless operation. Its point of access is a local area network (LAN).
 

Ø AI: 
Stands for Artificial Intelligence. This is the area of computer science focusing on creating machines that can engage on behaviors that humans consider intelligent. The ability to create intelligent machines has intrigued humans since ancient times, and today with the advent of the computer and 50 years of research into AI programming techniques, the dream of smart machines is becoming a reality. Researchers are creating systems which can mimic human thought, understand speech, beat the best human chess player, and countless other feats never before possible. 
 

Ø ACPI: 
Advanced Configuration and Power Interface. This interface was first introduced in 1996 and was developed to control computer devices power distribution. For example, if a device was currently not in use, the ACPI would turn this device off to create more power where necessary for smoother operation. 
 

Ø Active Matrix:
A type of LCD (liquid crystal display) structure that is actively controlled by a diode or transistor. This allows for each pixel to be independently controlled which produces excellent color resolution.
 

Ø Active X:
A software technology developed by Microsoft. This is based on other technology Microsoft developed such as; COM (Component Object Model) and OLE (Object Linking and Embedding). Active X defines how applications share information. While Active X gives much more freedom as to how certain applications are viewed, it has inherent security risks.
 

Ø Actuator:
Device that performs an action or outputs a signal in response to a signal from a computer.
 

Ø Addressing:

   A method of identifying a resource (such as a program) or piece of information (such as a file) on a network. Methods of addressing vary considerably from network-to-network.

Ø Automated Document Feeder(ADP)
As the name suggest ADP is used to automatically feed pages into the scanners and copiers. This helps in facilitating faster work as each individual page does not need to be fed into the copier or scanner.

Ø Adware:
A software program that is designed to run once a web page has been accessed. This is usually in the form of banner or popup advertisements. Adware can also be designed to be installed on your system without your consent or knowledge. These forms of adware are usually referred to as "spyware" and are used to monitor your surfing habits so that their software can deliver better targeted advertisements. In other instances, the software can be designed to monitor your keyboard keystrokes so that the author of the software can gain access to your password protected accounts. This type of adware is referred to as "malware" due to its malicious intent.
 

Ø Aero:
Aero is the name of Windows Vista's new graphical interface that gives users an exciting new desktop look and feel. It stands for: Authentic, Energetic, Reflective and Open. It is designed to be very aesthetically pleasing. It's effects include:

-Glass effects
-Advanced Window Management features
-Desktop Composition which creates a more stable experience
 

Ø AGP: 
Stands for Accelerated Graphics Port. This interface specification was developed by Intel Corporation. It was designed to give lower costing graphics cards much faster access to the main memory on personal computers. AGP ports run at 66 MHz and can transfer data up to 2133 MB/sec. An AGP is used with games and applications to store and retrieve larger and better 3D shapes and textures.
 

Ø AGTL Signaling:
(Assisted Gunning Transistor Logic) AGTL and AGTL+ use the same signaling protocol only at different voltage levels. AGTL+ operates at 1.5V signaling levels, while AGTL operates at 1.25V. 

Ø Alert Box
The little box that pops up to inform you that the computer you are working on is about to perform an operation which may have damaging consequences is called the alert box. In a way, the alert box is certainly a help, especially when you might have typed in a command absentmindedly and would not like to go through with it! Most of the time you can make it go away by a click of the buttons available or by using the mouse.

Ø Audio Interchange File Format(AIFF)
AIFF is an audio format used for storing high quality sampled audio data. As an AIFF is of a high quality it can be burned on to an audio CD,and despite being created by Apple, the files can be read by the audio programs on the MAC and PC with ease.

Ø Algorithm:

   A formal set of instructions that can be followed to perform a specific task, such as a mathematical formula or a set of instructions in a computer program.
 

Ø Alias:
A shortcut or 'friendly name' that points to a file folder or application. As an example, when you enter in a user name for an application, this user name would be an 'alias'.
 

Ø Aliasing:
This refers to the distortion in a sound or image generation. A sound distortion occurs when digitally recording high frequencies with a low sample rate. An image distortion occurs when a printer, monitor or graphic file has an insufficient amount of resolution to display an image properly.
 

Ø AMD:
(Advanced Microchip Devices) A semiconductor manufacturer and is a major competitor of Intel. They manufacture the Athlon, Duron, and K6 CPU chips.
 

Ø Analog: 
Anything whose behavior corresponds with the behavior of something else, especially if the correspondence varies continuously rather than in steps. For example, the height of the liquid in a thermometer is an analog of the temperature. The signals that go from a computer to a composite monitor are analog voltages. 

Ø Apache:

    Apache is the most popular Web server software. It enables a computer to host one or more websites that can be accessed over the Internet using a Web browser. The first version of Apache was released in 1995 by the Apache Group. In 1999, the Apache Group became the Apache Software Foundation, a non-profit organization that currently maintains the development of the Apache Web server software.

    Apache's popularity in the Web hosting market is largely because it is open source and free to use. Therefore, Web hosting companies can offer Apache-based Web hosting solutions at minimal costs. Other server software, such as Windows Server, requires a commercial license. Apache also supports multiple platforms, including Linux, Windows, and Macintosh operating systems. Since many Linux distributions are also open-source, the Linux/Apache combination has become the most popular Web hosting configuration.

    Apache can host static websites, as well as dynamic websites that use server-side scripting languages, such as PHP, Python, or Perl. Support for these and other languages is implemented through modules, or installation packages that are added to the standard Apache installation. Apache also supports other modules, which offer advanced security options, file management tools, and other features.

     Most Apache installations include a URL rewriting module called "mod_rewrite," which has become a common way for webmasters to create custom URLs.

     While the Apache Web server software is commonly referred to as just "Apache," it is technically called "Apache HTTP Server," since the software serves webpages over the HTTP protocol. When Apache is running, its process name is "httpd," which is short for "HTTP daemon."

Ø AppleTalk: 

     A protocol suite developed by Apple Computer in the early 1980s, was developed in conjunction with the Macintosh computer. AppleTalk's purpose was to allow multiple users to share resources, such as files and printers. The devices that supply these resources are called servers, while the devices that make use of these resources (such as a user's Macintosh computer) are referred to as clients. Hence, AppleTalk is one of the early implementations of a distributed client/server networking system. 
 

Ø AppleScript: 
It is a kind of English-like language that is used to write specific script files which have the ability to automate the actions of the computer systems and applications that run on it. 
 

Ø AppleShare: 
   This is Apple's network system. It is to the Macintosh what FTP is to the PC. 
 

Ø Applet: 
An applet is a small program generally written in the Java programming language that was designed to provide interactivity on web pages.
 

Ø Application: 
    An application is a program that is designed to perform specific tasks. A few examples of some popular applications are:

-Microsoft Windows
-Microsoft Word
-Adobe Photoshop
-Internet Explorer 
 

Ø Application Server:
This is a specialized server based in a client/server network that has the sole responsibility of running specific applications within that network.
 

Ø Archie: 
Or ArchiePlex which is an Archie gateway for the World Wide Web. It can locate files on Anonymous FTP sites in the Internet.
 

Ø Archive:
This usually defines old files that are no longer in use and are stored for possible future use or reference.
 

Ø Arithmetic Logic Unit (ALU):
Arithmetic Logic Unit. This is a mathematical core circuitry that applies to all computers central processing units (CPU). ALU mathematically and logically calculates the results of binary data.

Ø ARP:

    Stands for "Address Resolution Protocol." ARP is a protocol used for mapping an IP address to a computer connected to a local network LAN. Since each computer has a unique physical address called a MAC address, the ARP converts the IP address to the MAC address. This ensures each computer has a unique network identification.

    The Address Resolution Protocol is used when information sent to a network arrives at the gateway, which serves as the entrance point to the network. The gateway uses the ARP to locate the MAC address of the computer based on the IP address the data is being sent to. The ARP typically looks up this information in a table called the "ARP cache." If the address is found, the information is relayed to the gateway, which will send the incoming data to the appropriate machine. It may also convert the data to the correct network format if necessary.

    If the address is not found, the ARP broadcasts a "request packet" to other machines on the network to see if the IP address belongs to a machine not listed in the ARP cache. If a valid system is located, the information will be relayed to the gateway and the ARP cache will be updated with the new information. By updating the ARP cache, future requests for that IP address will be much quicker. While this may seem like a complex process, it usually takes only a fraction of a second to complete. If only it was just as easy to find old receipts when you need them.

 

Ø ASCII: 
It stands for "American Standard Code Information Exchange" and is pronounced (ask-ee). A standard code or protocol for displaying characters and transferring data between computers and associated equipment. It was developed for the purpose of information exchange among the following:

-Associated equipment  
-Data communications systems  
-Data processing systems 

      There are 128 standard ASCII codes each of which can be represented by a 7      digit binary number: 0000000 through 1111111.

Ø Asynchronous: 
1 : not synchronous; not occurring or existing at the same time or having the same period or phase.
2 : of, used in, or being digital communication (as between computers) in which there is no timing requirement for transmission and in which the start of each character is individually signaled by the transmitting device. 
 

Ø  ASP: 

   In computing, this stands for "Active Server Pages". Developed by Microsoft and is designed as a web server extension which is a default scripting language for writing VBScript.