A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally.^[1] A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core component of the computer.

A peripheral can be categorized based on the direction in which information flows relative to the computer:

• The computer receives data from an input device; examples: mouse, keyboard, scanner, game controller, microphone and webcam

• The computer sends data to an output device; examples: monitor, printer, headphones, and speakers

• The computer sends and receives data via an input/output device; examples: storage device (such as disk drive, solid-state drive, USB flash drive, memory card and tape drive), modem, router, gateway and network adapter

Many modern electronic devices, such as Internet-enabled digital watches, video game consoles, smartphones, and tablet computers, have interfaces for use as a peripheral.