A computer is a device that has been programmed to carry out different logical and arithmetic operations. A computer system consists of interconnected computers operating independently having a centralized storage and different peripheral devices, for example printers, scanners or routers. The different parts of a computer system are classified into four basic units, input, storage, central processing and output unit. Input unit: Input is done with the help of input devices. They are keyboard and mouse, trackball, touchpad and scanner. The keyboard resembles a typewriter. It has some additional function keys for special functions. The mouse is used to Continue reading...