1) Mechanical: This is a type of computer mouse that has a rubber or metal ball on its underside and it can roll in every direction. Sensors within the mouse, which are mechanical, detect the direction in which the ball is moving and moves the pointer on the screen in the same direction. A mouse pad should be used under the mouse to run on.

2) Optomechanical: This type is the same as the mechanical mouse except that it uses optical sensors to the motion of the ball. A mouse pad should be used under the mouse to run on.

3) Optical: This type uses a laser for detecting the mouse's movement. You don't need a mouse pad but you can use one made for optical mice. Optical mice do not have any mechanical moving parts. This type responds more quickly and precisely than the mechanical and optomechanical mice and now that they have been around awhile the price is pretty comparable.

How does a computer mouse hook up to the computer?

Serial mouse: these ones connect directly to an RS-232C serial port or a PS/2port. This is the simplest type of connection.

PS/2 mouse: connects to a PS/2 port. USB mice

Cordless mouse: These are not physically connected to the computer. They rely on infrared or radio waves to communicate with the computer. Cordless are more expensive than both the serial and bus mouse. The nice thing is that there is no cord to constrain or get in your way.