Touch pad

Definition
A touch pad (also spelled touchpad) (or trackpad) is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on the computer screen. Touch pads are a common feature of laptop computers, and they are also used as a substitute for a mouse where desk space is scarce. Because they vary in size, they can also be found on personal digital assistants (PDAs) and some portable media players.