A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core component of the computer. It can communicate with a computer through wired or wireless connections. Many modern electronic devices, such as Internet-enabled digital watches, video game consoles, smartphones, and tablet computers, have interfaces for use as a peripheral.
Mouses and keyboards became the standard for computer peripheral input devices in the 1970s, while memory storage devices continued to be developed in new ways. Output devices, such as monitors, began as cathode rays, before switching to LCD monitors in the 1980s.