A mouse is an input device that is used to point and select an option on the VDU. A mouse can be classified on the basis of the number of buttons it has, the technology it uses and the kind oi interface it has with the computer.

A mouse may have one, two or three buttons. The function of each button is determined by the program that uses the mouse. A software package may use one, two or all three of them. In its simplest form, a mouse has one button. Moving the mouse on a flat surface produces a corresponding movement of a pointer on the screen. Placing the pointer on an option and clicking the button results in selecting that option.

Two-button Mechanical Mouse

Two-button Mechanical Mouse

A mouse may be classified as a mechanical mouse or an optical mouse, on the basis of the technology it uses. In a mechanical mouse, the ball that projects through the bottom surface rotates as the mouse is moved along a flat surface. The direction of rotation is detected and relayed to the computer by the switches inside the mouse. Microsoft, IBM and Logitech are some weil-known makers of the mechanical mouse.

An optical mouse uses a light beam instead of a rotating ball to detect movement across a specially patterned mouse pad. MSC Corporation makes the optical mouse that uses LEDs and photo-detectors to trap movement.