A touchpad is a device for pointing on a computer display screen. It is an alternative to the mouse.
It was invented by George E. Gerpheide in 1988. The touchpad is a flat area, located beneath your keyboard. When you move your finger across the touchpad surface a corresponding mouse pointer moves around your computer screen. With a touchpad, you perform clicking actions to open or select things on screen by using the right and left buttons on the bottom of the touchpad.
Under the soft skin of the touchpad, there is an array of sensors which create an electrical field. The finger changes the character of the electrical field, allowing the user to drag a cursor across the screen.