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 on desktops, where desk space is scarce. Because trackpads can be made small, they can be found on personal digital assistants (PDAs) and some portable media players. Wireless touchpads are also available, as detached accessories.
Closeup of a touchpad on an Acer CB5-311 laptop
Closeup of a touchpad on a MacBook 2015 laptop
Optical trackpad of the BlackBerry Curve 8520 in the red circle
A Microsoft Surface tablet. The touchpad is the rectangle near the bottom of the keyboard.
A pointing device is a human interface device that allows a user to input spatial data to a computer. Graphical user interfaces (GUI) and CAD systems allow the user to control and provide data to the computer using physical gestures by moving a hand-held mouse or similar device across the surface of the physical desktop and activating switches on the mouse. Movements of the pointing device are echoed on the screen by movements of the pointer and other visual changes. Common gestures are point and click and drag and drop.
A computer mouse
Touchpad and a pointing stick on an IBM notebook
Trackpoint
An elder 3D mouse