See HP TouchPad
The built-in pointing device on all laptop and netbook computers. Also called a "trackpad," the touchpad provides a small, flat surface to slide one's finger over. Residing below most touchpads, two physical buttons emulate the left and right mouse buttons; however, the touchpad surface can often be tapped as a substitute for pressing the left button. In addition, either the entire touchpad area or only one side of the surface may be used to emulate the mouse's scroll wheel.
Popularized by Apple's Magic Trackpad, newer multitouch devices accept gestures from two or more fingers to activate common functions such as scrolling, next page, previous page and zoom. See mouse
, pointing stick
and Magic Trackpad
The touchpad became standard on laptops, but external units for desktop computers are also available (see Magic Trackpad