Computer is one of the greatest wonders of modern science. It is a machine that can accomplish many complex jobs. It has brought revolutionary change in the present world. It renders great service to us. It can do any kind of difficult calculation within seconds and store records of millions of information. Necessary information can be regained by pressing a button when it is required. Now-a-days computer are used in all spheres like medical science, education, commerce, agriculture, industry and offices. Medical science has advanced more with the help of computer. It is used to diagnose various diseases. Computer has lessened our load of works and made our life easy and comfortable. It works like a magician. It has saved us from doing a lot of monotonous works. It has become a part and parcel of our modern civilization. We cannot go a single day without it.