Definition: Any auxiliary device such as a mouse, keyboard, hard drive, etc. that connects to and works with the computer in some way.
Usually, the word peripheral is used to refer to a device external to the computer, like a scanner, but the devices located inside the computer case are also technically peripherals.
Also Known As: external peripheral, auxiliary component
Examples:
"Many of the external peripherals I own, such as my scanner and printer, connect to the peripheral ports on the back of my computer."
