Following are some of the important input devices which are used in a computer − Keyboard Mouse Joy Stick Light pen Track Ball Scanner Graphic Tablet Microphone Magnetic Ink Card Reader(MICR) Optical Character Reader(OCR) Bar Code Reader Optical Mark Reader(OMR) Keyboard Keyboard is the most common and very popular input device which helps to input data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions. Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet. The keys on the keyboard are as follows − S.No Keys & Description 1 Typing Keys These keys include the letter keys (A-Z) and digit keys (09) which generally give the same layout as that of typewriters. 2 Numeric Keypad It is used to enter the numeric data or cursor movement. Generally, it consists of a set of 17 keys that...