The mouse is a user input device that enables you to communicate with your PC. By moving the mouse and pressing the two or three buttons, you can highlight and select images on the screen to give directions to your PC. Some mice offer a wheel to aid in the scrolling of a window without having to move the mouse.
A mouse is usually connected by a wire but wireless mice are also available. Wired mice may use a serial, PS/2 or a USB port. Other variations of mice available include the trackball and touchpad.
The mouse detects movement either as a ball underneath the mouse rolls along your desk or by using a light inside the mouse and measuring the reflection from the desktop.