Human Interface Device

Any device used to facilitate interaction between a human and a computer, including keyboards, mice, trackballs, joysticks, touchscreens, switches, and eye-tracking systems. The USB HID standard defines a protocol for these devices that enables plug-and-play compatibility. For people with motor impairments, standard human interface devices are often inaccessible, driving the need for adaptive alternatives such as single-switch interfaces, head-tracking mice, sip-and-puff controllers, and custom-designed input devices tailored to individual motor abilities.