what is a trackball
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 axesâlike an upside-down mouse with an exposed protruding ball. The user rolls the ball to position the on-screen pointer, using their thumb, fingers, or commonly the palm of the hand while using the fingertips to press the mouse buttons. Compared with a mouse, a trackball has no limits on effective travel; at times, a mouse can reach an edge of its working ...