Trackball: A trackball has a ball that can rotate freely. Instead of moving the device like a mouse, you can roll the ball with your thumb to move the pointer.
Touchpad: A touchpad — also called a trackpad — is a touch-sensitive pad that lets you control the pointer by making a drawing motion with your finger. Touchpads are common on laptop computers.
Credits:
Created with images by Skitterphoto - "chess ipad 3d" • AlexKingCreative - "mouse apple magic mouse" • TLSPAMG - "mouse wireless technology"