A fabric-covered rubber pad roughly 9" square that provides a smooth surface for rolling a mouse. Since the advent of optical mice, mouse pads are no longer as essential as they were in the past. However, mouse pads often include wrist rests that people find comfortable. See
optical mouse.
Precise Mousing Surface
This 3M mouse pad is more efficient than the ubiquitous rubber pad. Less than 1/16" thick, its microstructured surface contains peaks and valleys (top left) that make the mouse roll smoother and more precisely. (Image courtesy of 3M.)