The mouse is a pointing device used to move a cursor on the screen and allowing objects to be selected, moved and manipulated using the buttons. The consistent action of pressing (clicking) on a button in order to carry out an action is called a "click".
The first mouse was invented and developed by Douglas Carle Engelbart of the Stanford Research Institute (SRI): it was a wooden mouse containing two perpendicular discs and connected to the computer by a pair of twisted wires.
The mouse is generally plugged in to the back of the central processing unit, into the motherboard, with a green PS/2 connector:
Some mice, with advanced functionalities sometimes have a USB connector.
There are several types of mice, classified according to the positioning technology on the one hand and the data transmission to the central processing unit on the other.
We can therefore distinguish several large categories of mice:
The mechanical mouse comprises of a ball upon which two rollers turn. These rollers each comprise of a notched disc which turns between a photodiode and LED (Light Emitting Diode) allowing the light to pass through in sequence. When the light passes through, the photodiode sends a bit (1), when it meets an obstacle, the photodiode sends a zero bit (0). Using this information, the computer knows the position of the cursor and even its speed.
Tip: As you use it, dust settles on the mouse rollers preventing them from turning correctly and causing strange reactions in the cursor. To remedy this, simply open the cage containing the ball and clean the rollers (with a toothbrush for example).
The optical mouse operates by analysing the surface on which it moves. So, an optical mouse is comprised of an LED, an image acquisition system (IAS) and a digital signal processor (DSP).
The LED is responsible for shining on the surface so as to enable the IAS to get an image of the surface. The DSP, through analysing the microscopic characteristics of the surface determines the horizontal and vertical movement.
Optical mice operate on any slightly uneven or even colored surface. The main advantages of this type of pointing device in comparison to the mechanical mouse are greater precision along with less dirtiness.
Cordless mice are more and more popular because they can be used without physically being connected to the computer, which gives a sensation of freedom.
There are also several categories of cordless mice, depending on the technology used:
Mice are increasingly equipped with a wheel. The wheel, generally located between the right and left buttons makes it possible to scroll through pages while enabling the user to move the cursor on the screen.