Mouse is a handly input device which can be moved on a smooth surface to stimulate the movement of cursor i.e. desired on a display screen.
User can move the mouse, stop it a point where the pointer is to be located and with the help of buttons, make selection of choices. Stanford Research Institute invented the name mouse. It fully controls GUI(Graphical User Interface). A mouse may be classified as a mechanical mouse or an optical mouse, on the basis of technology it uses. An optical mouse uses a light-beam instead of a rotating ball to detect movement across a specially patterned mouse pad. 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 well-known manufacturers of the mechanical mouse.

In 1981, first integrated mouse came with the Xerox 8010 star information system. Some people use a mousepad to improve traction for the mouseball. User adjusted the sensitivity of the mouse according to that how fast it moves across the screen. It usually has two or three buttons using which the user can select options from the screen. The function of each button is determined by the program that uses the mouse. Moving the mouse on a flat surface produces a corresponding movement of a pointer on the screen.

Varieties of mouse were:-

1) Trackball mouse- In this mouse, the ball is rolled at one place with the thumb, fingers and palms rather than rolling the mouse on the table top.

2) Joystick mouse- It usually includes two upright sticks, which moved with hand and button pressed on either stick.

3) Lightpen mouse- It utilises a light-sensitive detectors, requiring you to hold apen and point it at the screen.

4) Wireless mouse- This mouse is a mouse without cable. It works upto one and a half meters away from the computer.

5) Touchpad mouse- It is a small, flat, rectangular pointer that is sensitive to pressure and motion. These devices are mostly used on portable computers.