A computer is a great invention of the modern technology. It is generally a machine which has capability to store large data value in its memory. It works using input (like keyboard) and output (like printer) devices. It is very simple to handle the computer as its functioning is so common that a child can handle it. It is a very reliable device which we can carry with us and use anywhere and anytime. It allows us to make changes in the already stored data as well as store new data. Computer is a new technology which is used in offices, banks, educational institutions, etc.