What is touchpad?
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 electric field allowing the user to
drag a cursor across the screen.
(From Manorama TELL ME WHY No. 117)