Input is any data and instruction entered into the memory of a computer. An input device is any hardware component that allows users to enter data and instruction into a computer. The examples of input devices are keyboard, mouse, scanner, touch screen and digital pen. There are also other types of input that are voice input and audio input.
Voice input is the process of entering input by speaking into a microphone. Uses of voice input include instant messaging that support voice conversations, chat room that support voice chat, internet telephony, and voice recognition.
Audio input is the process of entering any sound into the computer such as speech, music and sound effect. To enter high quality sound into a personal computer, the computer must have a sound card.
Output is data that have been processed into a useful form. An output device is any hardware components that conveys information to one or more people. Commonly used output devices include display devices; printers; speaker, headphone and earphone; fax machine and fax modems; multifunctions peripherals; and data projectors. Examples of display devices are LCD monitors and screens, Plasma monitors and CRT monitors.