Trackballs
A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse: the user rolls the ball with a thumb, fingers, or the palm of the hand to move a cursor on the screen.

What is a Trackball? Functions, Types, FAQs, and more!
What is a trackball? This incredible gadget was used by geeks before the mouse came out. Learn about it now!