Basically, computer is an electronic device or a machine which has ability to manipulate, store, process and receive data from other devices in the form of electronic signals in particular language. The word “Computer” was derived from Latin term “Computare” which means to calculate or programmable machine. In 19^th century first mechanical computer was invented by an English mechanical engineer and polymath Charles Babbage. Similarly, the first analog computer was designed by Scottish mathematician and physicist Sir Thomas Williams in 1972. With the passage of time, German mechanical engineer Konrad Zuse made electro mechanical relay computer in 1939. As a consequence, modern computers have been evolved recently which has revolutionized the computer science department. These computers consist of transistors, integrated circuits with decoders, processors and artificial intelligence.  With the modification of central processing unit (CPU) computer has built in input devices which encompasses computer keyboard, digital camera, graphics, scanner, joystick, microphone, mouse, real time clock, track ball and touch screen.  It is also available with output devices which include LCDs, printers, speakers, projector and sound card. It also has enhanced memory option with multi tasking and multi processing facilities. Computers are capable to connect on video with other computer which is placed thousands of miles away from that computer with the help of internet. It also has artificial intelligence by which computer has given authority to take decision without asking for command from users. It is invention of modern age.