A peripheral is a device attached to a host computer behind the chipset whose primary functionality is dependent upon the host, and can therefore be considered as expanding the hosts capabilities, while not forming part of the system's core architecture.

Overview

Some of the more common peripheral devices are printers, scanners, disk drives, tape drives, microphones, speakers, and cameras. Peripheral devices can also include other computers on a network system.

Some people do not consider internal devices such as video capture cards to be peripherals because they are added inside the computer case; for them, the term peripherals is reserved exclusively for devices that are hooked up externally to the computer. It is debatable however whether PCMCIA cards qualify as peripherals under this restrictive definition, because some of them go fully inside the laptop, while some, like WiFi cards, have external appendages.

The term is different from computer accessories: Computer peripheral has a narrow meaning that refers only to the input output devices of a computer, whereas, computer accessories has a broader meaning, that refers, all the parts that support a computer which includes motherboards, sensors, chips, including all the input and output devices