A 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 screen. Touchpads are a common feature of laptop computers, and are also used as a substitute for a mouse where desk space is scarce.

Two-layer capacitive touchpad and method of making same
Visual touchpad: a two-handed gestural input device
The tactile touchpad
Clash of the Tablets: From iPad to TouchPad, 6 Slates Compared
Method and apparatus for scroll bar control
Fitts' Law as a Research and Design Tool in Human-Computer Interaction
Multi-touch sensing through frustrated total internal reflection
Multi-touch sensing through frustrated total internal reflection
Testing pointing device performance and user assessment with the ISO 9241, Part 9 standard
Interacting with large displays from a distance with vision-tracked multi-finger gestural input