know computer

What is computer?

A computer is a device or programmable machine for making calculations or controlling operations that are expressible in numerical or logical terms accordingto some predetermined program of instruction at a high speed and with great accuracy.


The key components that makes a computer system is::
Hardware

Software



Computer Hardware

• motherboard::

A motherboard is the physical arrangement in a computer that contains the computer's basic circuitry and components and controlsthe various peripherals attached to a computer.The CPU, ROM chips, SIMMs, DIMMs, RIMMs and interface cards are plugged into the motherboard.

• RAM(random access memory)::

The working memory of a computer where data and programs are temporarily stored. RAM only holds information when the computer is on.The contents of RAM disappears when the computer is switched off.

• HDD(hard disk drive)::

This is the main storage device in a computer.The mechanism that reads and writes data on a hard disk.It is a computer storage device that stores data on rotating magnetic surfaces.Hard disk drives are sometimes called Winchester drives, Winchester being the name of one of the first popular hard disk drive technologies developed by IBM in 1973.

• processors::

The main "brain" of the computer, where the information is processed and calculations are done.It contains the circuits that control and perform the execution of computer instructions.

• keyboard::

An input device used to communicate with the computer.An arrangement of letter, number, and special function keys that acts as the primary input device to a computer.

• monitor::

A screen which allows the user to watch and interact with the computer.The screen for viewing computer information is called a monitor.

Software

Software is the general term for information that's recorded onto some kind of medium.
our computer is a hardware device that reads software too. Most of the software on our computer comes in the form of programs. A program consists of "instructions" that tell the computer what to do, how to behave.
Just as there are thousands of albums we can buy on CD for our mp3 player, and thousands of movies we can buy to play on our DVD player, there are thousands of programs that we can buy to run on our computer.When we buy a computer,we don't automatically get every program produced by every software company in the world.we usually get some programs.
For example, when we buy a computer it will probably have an operating system (like Windows XP) already installed on it.but,suppose if we dont have "windows vista" then we cant enjoy the features of newly launched,multifeatured vista.
Perhaps we're wondering what programs are installed on our computer. Usually when we buy a computer, they tell us what programs we're getting with it. every program that's currently installed on our computer is listed in our All Programs menu (assuming we're using Windows XP). The All Programs option on the Start menu provides access to all our installed programs. When we first click on (or just point to) the All Programs option, the All Programs menu that appears will show icons and name of program groups, as well as some programs.

Software is often divided into two categories::

systems software ::Includes the operating system and all the utilities that enable the computer to function.
appltions software ::Includes programs that do real work for we users. For example, word processors, database management systems etc fall under the category of applications software.