A pointing device that is moved by hand around a flat surface: the movements in the x- and y-directions on the surface are communicated to a computer and cause corresponding movements of the cursor on the display. The mouse' movements are sensed by the rotation of a ball in its base, or by optical sensors.
The mouse has one or more buttons to indicate to the computer the desired function. It is normally connected by cable to the computer or may communicate by means of radio, infrared, or optical signals. Some mice incorporate a finger-operated roller to control scrolling.