In this lesson we have discussed about the major characteristics of computer. The speed, accuracy, memory and versatility are some of the features associated with a computer. But the computer that we see today has not developed over night. It has taken centuries of human effort to see the computer in its present form today. There are five generations of computer. Over these generations the physical size of computer has decreased. On the other hand, the processing speed of computer has improved tremendously. We also discussed about the varieties of computers available today. Various application areas of computers have also been discussed.