Science has discovered several wonders and computer is one of them.It is an ultra modern electronic device for storing and analyzing information fed into it. It has no ability to do anything by itself. It factory on the basis of guidelines given by the operator. A computer consists of five main components. They are the input unit, the out put unit, the memory unit, the control unit and the arithmetic unit. Computer is of great use to us. It renders great service to mankind. It is like Aladin’s magic lamp or magic wand. It has lessened our work loads and made our life easy and comfortable.