External computer parts are those that connect to the case, often to provide ways to input or output data. Most computers use a keyboard and mouse as external input devices and a monitor as an output device. Speakers, printers, modems, network routers and external storage devices are other external devices.
External computer components connect to the motherboard through a series of ports on the computer case. Many components have their own dedicated port connections, such as those to connect audio equipment or the computer monitor. Others may share a single type of connector, such as the USB, that connects everything from keyboards and mice to game pads and external hard drives.