An input device is a peripheral (piece of computer hardware device) used to provide data and control signals to computer. To interact with computer, we always need an input device. Examples of input devices include keyboards, mouse, scanners, digital cameras and joysticks.
A computer keyboard is one of the primary input devices that looks similar to typewriters, but with some additional keys. Keyboards allow you to input letters, numbers, and other symbols into a computer that can serve as commands or be used to type text.
A pointing device is any human interface device that allows a user to input spatial data to a computer. Movements of the pointing device are captured on the screen of computer. A number of pointing devices are used in computer, some of them are as follows:
- Mouse: Mouse is the most commonly used input pointing device. Earlier mouse use a ball underneath it, the cursor on the screen follows the motion of the mouse. Now-a-days optical mouse are available which uses laser instead of ball.
- Trackball: Instead of moving the whole mouse around, the user roll the trackball only, this is attached on the top or side of keyboard.
- Glide pad: Gilde pad is a touch sensitive pad for controlling the cursor. The user slides finger across the pad and the cursor follows the finger movements. The glide pad is very popular in laptops.
- Joy Stick: The motion of cursor is controlled by a vertical stick or arrow buttons. A joystick gives more natural-feeling control for motion in games, especially those where we are flying a plane or spaceship.
- Pen input: A Pen input is generally used in personal digital Assistants (PDA). By writing with pen on PDA screen the PDA recognizes our hand writing.
- Touchscreen: It is a very popular source of input in mobile phone now days. The touchscreen makes selection by just touching the screen.
A terminal can also be considered as an input device. It consists of a keyboard and a screen.
- A dumb terminal: A dumb terminal has no ability to process or store data, it is linked to a mini computer, mainframe or a super computer.
- An intelligent terminal: I is a smart or programmable terminal which can process or store data.
- Point of sale (POS) terminal: POS is an example of a special purpose terminal, it is generally used to make credit-debit card transactions in retail shops.
Multimedia is a combination of sound and images with text and graphics. This would include movies, animations, music, sound effects etc.
In order to capture sounds, a computer uses microphones. Microphones can capture sounds from the air.
A digital camera or a web cam can be used for video input. A digital camera takes photos but records the videos. A web can is a tiny video camera that sends pictures directly to computer or over internet.
It captures a whole page and converts it to digital image. It is generally used in photo copy machines.
It is used at the retail shops to track an article details and calculate the sale amount at the cash counter. A special kind of scanner is used to scan the bar codes.
Optical Character Recognition
OCR takes a scanned image and converts it in the form of characters. The OCR converted documents can be edited with a word processor