touchpad

A touchpad, also called a trackpad, is a flat pointing device that translates finger movements into cursor motion on a computer screen. It is most commonly built into laptop keyboards but is also available as an external peripheral for desktops. Touchpads typically support tapping to click, either as a substitute for or in addition to physical buttons.

Most modern touchpads use capacitive sensing to detect finger position and movement across a smooth surface. A grid of sensing elements records coordinates, sometimes with pressure sensing. Some older or specialized pads use resistive or optical methods. Multi-touch support enables gestures such as two-finger scrolling, pinch-to-zoom, and rotate, while edge or two-finger motions can emulate scrolling or navigation.

Designs vary: many pads include dedicated physical buttons, while others use a clickable surface or integrated click without separate buttons. Some models offer palm-rejection, sensitivity controls, and haptic feedback. Drivers and firmware from manufacturers add gesture customization and accessibility features.

Historically, touchpads were introduced in the late 1980s and became standard in laptops during the 1990s. They are produced by vendors such as Synaptics, Alps Electric, and Elan. External trackpads, including Apple's Magic Trackpad, extend use to desktop setups and provide similar multi-touch capabilities.