Author: admin
A pointer represents a small symbol on the screen. It usually appears on the screen in Graphical User Interface (GUI). For example, an arrow appears on the screen in Windows environment.
A pointing device is an input device that is used to control a pointer on the screen. Usually, the pointing device is used to select items on the screen, to select commands from commands menu, to draw graphs etc. For example, the engineers use pointing devices to draw graphs. The Mouse, Joystick, Trackball, Track pad, Light Pen etc. are examples of pointing devices.
Mouse
Mouse is a pointing input device. It is the most commonly used pointing device in Windows environment on the personal computers. The mouse has two or three buttons on the top of its body. Mouse is used to select any option from a group of options by pointing the mouse pointer on it and then clicking one of the mouse buttons.
A mouse also allows the user to create graphics such as lines, curves and freehand shape on the screen. The graphic designer cannot draw graphs without mouse. A mouse is connected to a serial port or USB port on the system unit.
The most popular types of mouse and their functions are:
Mechanical Mouse
It has a rubber or metal ball at its bottom and an electronic circuit containing sensors. When mouse is rolled over a flat surface the pointer moves in the same direction. The sensors detect the direction of movement of ball and electronic circuit translates the movement of the mouse into signals and then feeds it as input in the computer.
Optical Mouse
It has advance features and is more expensive than mechanical mouse. It has no ball inside it. It uses the laser technology to detect the mouse movement by optical sensors.
Cordless Mouse
Cordless or wireless mouse is not directly connected with computer. It uses the wireless technology, such as radio waves or infrared light waves. It enters input signals into the computer in similar way as cordless keyboard.
Trackball
A trackball is also a pointing input device. It is like a mouse but it is a stationary pointing device with a ball on it top. It is a hard box with a rolling ball at the top and one or more buttons that work just like mouse. The ball is rolled or rotated with finger to move the cursor or pointer around the screen. Like mouse specific item is selected by pointing with trackball and then pressing with one of the buttons. The trackball is usually available with laptop computers and is fixed on the keyboard.
Some cordless trackball are also available. They are not directly connected to the computer with wire and acts like a remote control for the pointer. They are especially useful when giving presentations because the presenter often walks around the room instead of sitting at a computer.
Touchpad
A touchpad is also known as track pad. It is small, flat, rectangular stationary pointing device. It has sensitive surface of 1.5 or 2 inches square. To move the pointer slid your finger tips across the surface of the pad. Some touchpad have one or more buttons around the edge of the pad that work like mouse buttons. The touchpad pointing device is mostly used in laptop computers and is built-in on the keyboard. You can also attach a track pad to a personal computer. The advanced keyboards also have built-in track pad.
Joystick
Joystick is also a pointing input device. It has small box with a moving handheld stick and buttons. The handheld stick is used to control the movement of pointer on the screen. The button of the joystick is presses to activate certain events.
The joystick input device is used to play games. It is also used with simulation software in education fields.