Peripherals
peripheral device
Peripheral device, also known as peripheral, computer peripheral, input-output device or input/output device, any of various devices (including sensors) used to enter information and instructions into a computer for storage or processing and to deliver the processed data to a human operator or in some cases, a machine controlled by the computer. Such devices make up the peripheral equipment of modern digital computer systems.
Input devices include typewriter-like keyboards; handheld devices such as the mouse, trackball, joystick, trackpad and special pen with pressure-sensitive pad; microphones, webcams and digital cameras. They also include sensors that provide information about their environment—temperature, pressure and so forth—to a computer. Another direct-entry mechanism is the optical laser scanner (e.g., scanners used with point-of-sale terminals in retail stores) that can read bar-coded data or optical character fonts.
Output equipment includes video display terminals, ink-jet and laser printers, loudspeakers, headphones and devices such as flow valves that control machinery, often in response to computer processing of sensor input data. Some devices, such as video display terminals and USB hubs, may provide both input and output. Other examples are devices that enable the transmission and reception of data between computers—e.g., modems and network interfaces.