A computer mouse is a pointing device held with the hand that discovers two-dimensional motion relative to a surface. This motion is interpreted into a pointer on a display to aid the smooth control of the graphical user interface (GUI). The computer mouse turns movements of the hand backward and forward, left and right into similar electronic signals that in turn are used to move the pointer. The relative movements of the computer mouse on the surface are applicable to the position of the pointer on the screen, which signals the point where actions of the user take place, hence hand movement are replicated by the pointer.
Different ways of operating the computer mouse may cause specific things to occur in the HUI such as single-click, double-click, triple-click, drag and drop etc. Mouse gestures can be used to issue a command or map to a specific action. Example, in a drawing program, moving the mouse in a rapid “x” motion over a shape might delete the shape. Standard semantic gestures include pointing, menu traversal, drag and drop, crossing-based goal, rollover, and selection.
Computer mouse was always wired to the computer, but modern mice are cordless and they depend on short-range radio communication with the system they are connected to. Furthermore, computer mouse originally had a surface rolling ball for motion detecting, but the modern ones have replaced the rolling ball with optical sensors that have no moving part. Additionally, a computer mouse has a few more buttons to permit operation such as menu item selection on a display.
In order to transmit input, cabled computer mouse use a thin electrical cord that ends in a standard connector such as RS-232C, PS/2, ADB or USB. Cordless computer mice instead transmit data through infrared radiation or Bluetooth, although many cordless interfaces are themselves connected via the above mentioned wired serial buses.
Types of Computer Mouse
Optical and laser mice
They depend completely on one or more light-emitting diodes (LEDs) and an imaging array of photodiode to detect movement relative to the underlying surface. A laser mouse is an optical mouse that uses unified (laser) light.
 

 

Inertial and gyroscopic mice
These cordless mice is often referred to as “air mice” since they don’t need a surface to operate. Inertial mice use a tuning fork or other accelerometer to detect rotary movement for every axis supported. The user requires only little wrist rotations to move the cursor, thereby reducing user fatigue or “gorilla arm”.
3D mice

 

Often called bats, flying mice, or wands, these devices generally function through ultrasound and provide not less than three degrees of freedom. The wireless mouse was worn on a ring around a finger which enabled the thumb to access three buttons and was tracked in 3D by a base station. As a result of its insufficient resolution, It was discontinued.
Gaming mice
These mice are designed especially for use in computer games. They are made up of a wide array of controls and buttons with designs that differ radically from conventional mice, especially the ones designed for use in real-time strategy games such as Statecraft, or in multiplayer online battle arena games such as Dora 2.
Other types of computer mouse are ergonomic mice, pucks, tactile mice, mechanical mice etc.