The document discusses the keyboard and mouse as the primary input devices for computers. It begins by explaining how computers understand machine language and need input devices to convert human instructions. It then lists some common input devices like the keyboard, mouse, scanner and joystick. The document focuses on keyboards and mice, describing their functions and types. For keyboards it covers standard, multimedia and wireless keyboards while for mice it discusses serial, PS/2, optical and wireless mice. It provides advantages and disadvantages of each.