The computer as we see today is quite different from the one made in the beginning. The number of applications of computer has increased and the speed and accuracy of calculation has also increased. You have already experienced the impact of computers in our day-to-day life. Reservation of tickets in Air Lines and Railways, Payment of telephone and electricity bills, Deposits and withdrawals of money from banks, Business data processing, Medical diagnosis, Weather forecasting, etc. are some of the areas where computer has become extremely useful.