A computer is an electronic device which is used to perform a multitude of tasks. Now computers are of myriad types ranging from personal computers to super computers. Advanced integrated chips used in computers aid them to perform the work faster and with efficiency. The essential parts of a computer include ALU (arithmetic logic unit), Control Unit, Memory and the input and output devices. The accessory devices improve the functionality of the computers. Many of the essential accessories are provided with the computer and many are purchased later according to individual preference. Examples of computer accessories include computer keyboards, monitor, computer mouse, speakers, printers, scanners, webcam etc. Many accessories improve the efficiency of the system, but they should be checked for compliance with the system.