Touchpad

A touchpad or trackpad is a type of pointing device. Its largest component is a tactile sensor: an electronic device with a flat surface, that detects the motion and position of a user's fingers, and translates them to 2D motion, to control a pointer in a graphical user interface on a computer screen. Touchpads are common on laptop computers, contrasted with desktop computers, where mice are more prevalent. Trackpads are sometimes used with desktop setups where desk space is scarce. Wireless touchpads are also available, as detached accessories. Due to the ability of trackpads to be made small, they were additionally used on personal digital assistants (PDAs) and some portable media players.