An external peripheral device must have a corresponding?

A peripheral device is a device which allows the computer to obtain information from its periphery - This may be as simple as a power button (which does not directly control the supply of mains to the machine, but rather signals to the power supply) or a HID (Human Interface Device).

Examples of HID include Mice, Keyboard, joysticks and gamepads, trackballs, trackpads... In fact anything which we use to provide information to the computer.

Any device which is connected to the computer must have a method of communicating with software which is running on the computer.

Early peripheral devices were always connected with cables however today peripheral devices can connect via one of the following means:

Any radio frequency method (includes Bluetooth, Wi-Fi, etc)

Mobile Phone

Infra-red communications are less commonly used but still supported.

A device could communicate with the computer via a network, this could mean that the device can be connected 5 feet or 500 miles away and it will appear the same to the computer (except for network speed limits and delays)

I hope this helps!