Peripheral

A peripheral is a piece of computer hardware that is added to a computer to expand its abilities. The term also tends to be applied to devices that are hooked up externally through some form of computer bus like a USB. Typical examples include joysticks, printers and scanners.

Some people do not consider internal devices such as video capture cards to be peripherals because they are inside the computer case; for them, the term peripherals is reserved exclusively for devices that are hooked up externally to the computer.

The term has somewhat fallen out of modern usage; it was mainly used in the early days of the home computer market to refer to things like floppy disk drives and modems. Today most of these devices are installed inside the computer case, and external devices typically function on their own such as MP3 players and cell phones.