What is the difference between a trackball and a mouse?

A trackball can be viewed as a kind of upside-down mouse, allowing for the user to directly manipulate the exposed ball with the thumb, fingers or the palm of the hand. Both mice and trackballs are used as primary interfaces with a computer system, and they are used to either move a cursor or interact with a video game.

One of the key advantages of a trackball over the mouse is that a trackball does not require any desk space for use since many are handheld. Using a trackball has been compared to a joystick, and both are generally preferred by people who find their arm movements are unsteady when using a mouse.