The literal meaning of the word Computer in an instrument that Computes or does various calculations. Fundamentally, it is a calculating machine. It can perform various calculations like addition, subtraction, division, multiplication and so on. In fact, it can receive innumerable data and instructions and perform thousands of calculations within seconds and then give the results.

A pert from doing mathematical calculation, a computer has surprising capabilities of manipulating the input data according to logic and making conclusions as per instructions. The work which a man would otherwise do in thousands of days is done by the computer within minutes or hours. The modern computer is a very updated electronic instrument. A computer has two main aspects : the hardware and the software. The hardware is the machine itself and the software is a combination of various symbolic instructions or codes better known as computer language. It has mainly three components as input devices, the CPU or the Central Processing Unit and the output devices. The input devices  receive instructions in codes which are similar to human language.

The hardware of a computer can be thought of as the skeleton and the software as the flesh and blood if the whole computers were to be imagined of as a human being. The software or the programs virtually help the hardware function the way the user wants it to. The programs are of two types : one is the operating system and the other is the applications program. The computer can be classified according to its size, speed and internal structure. It is perhaps the strangest gift of science.