What is a Computer?

What is a Computer?

A computer is a machine that can be programmed to accept raw data, which is input, process it into meaningful information, which will be output, and store it away in a secondary storage device for safekeeping or later reuse.

Computers work under the control of a stored program, which can be changed.

To function, a computer system requires four main aspects of data handling:

• input
• processing
• output
• storage

Input

Input devices accept data in a form that the computer can use and then send the data to the processing unit.

Processing

The central processing unit (CPU) has the electronic circuitry that manipulates input data into information people want. The CPU executes program instructions.

Output

Output devices show people the processed data in a form that they can use easily.

Storage

Storage consists of secondary storage devices such as magnetic disks, tapes and CD ROMs, which can store data and programs outside the computer itself. These devices supplement memory, since memory can hold data and programs only temporarily.