Where as a computer mouse moves over the table surface, the trackball is

• Stationary

• Difficult to move

• Dragged

• Moved in small steps

...
Explanation: Trackball remains stationary when we move a computer mouse on a table. A ball held by a socket in a trackball (Pointing Device) moves in two axes (Upside & Down). Such kinds of computer mouse have a plastic case which consists of a ball on the top that moves cursers around the screen. Using a thumb or finger ball can be moved and the sensor inside the case detects the ball's direction.