The mouse is an input device used to point to a particular place on the screen. It sends the movement of itself in x and y coordinates to the system and selects in order to perform one or more actions. It can be used to select menu commands, size windows, start programs, etc. The most conventional kind of mouse has two buttons on top: the left one being used more often.

1. Mouse Actions:

(i) Left-click : used to select an item.

(ii) Double click: used to start a program or open a file.

(iii) Right-click: usually used to display a set of commands.

2. Drag and Drop:

It allows you to select and move an item from one location to another. To achieve this, place the cursor over an item on the screen, click the left mouse button and while holding the button down, move the cursor to where you want to place the item, and then release it. There are two main kinds of mouses. A ball-type mouse uses a rubber ball for rolling and an optical mouse by bouncing a light beam off to work desk or mouse, pad.

3. The working principle of the ball computer mouse:

As the user moves it across the desk, the ball rolls under its own weight and pushes against two plastic rollers linked to thin wheels. One of the wheels detects movements in an up-and-down direction (like the y-axis on graph/ chart paper); the other detects side-to-side movements (like the x-axis on graph paper).

4. The working principle of the optical mouse:

An optical mouse shines a bright light down onto the desk or pad from an LED, mounted on the bottom of the mouse. The light bounces straight back up off the desk into a photocell, also mounted under the mouse, a short distance from the LED. The photocell lens magnifies the reflected light, so the mouse can respond more precisely to hand movements. As the mouse moves around the pattern of reflected light changes and the chip inside the mouse identifies the movement. This movement is converted into signals and sent to the computer to move the cursor accordingly.