Provide means of communication between a computer and outer world.
Also known as peripheral devices because they surround the CPU and memory of a computer system.
Input devices are used to enter data from the outside world into primary storage.
Output devices supply results of processing from primary storage to users.
Allow data entry into a computer system by pressing a set of keys
(labeled buttons) neatly mounted on a keyboard connected to a
computer system
101-keys QWERTY keyboard is most popular.
Used to rapidly point to and select a graphic icon or menu item from multiple options displayed on the Graphical User Interface
(GUI) of a screen.
Used to create graphic elements on the screen such as lines,curves, and freehand shapes.
Some commonly used point-and-draw devices are mouse, track ball, joy stick, light pen, and touch screen.
Mouse is most popular pointing device. It is a very famous cursor-control device having a small palm size box with a round ball at its base which senses the.
movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed.
Generally it has two buttons called left and right button and a wheel is present between the buttons. Mouse can be used to control the position of cursor on screen, but it cannot be used to enter text into the computer.
Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted and by moving fingers on ball, pointer can be moved. Since the whole device is not moved, a track ball requires less space than a mouse. A track ball comes in various shapes like a ball, abutton and a square.
Most simple , intuitive , and easiest to learn C all input devices and enable to choose.
Input devices that enable direct data entry into a computer system from source
Documents.
Eliminate the need to key in text data into the computer.
Due to reduced human effort in data entry, they improve data accuracy and
also increase the timeliness of the information processed.
Demand high quality of input documents Some data scanning devices are also capable of recognizing marks or Characters.
Form design and ink specification usually becomes more critical for accuracy.
Scanner is an input device which works more like a photocopy
machine. It translates paper documents into an electronic format
for storage in a computer.
It is used when some information is available on a paper and it is
to be transferred to the hard disc of the computer for further
manipulation.
Scanner captures images from the source which are then
converted into the digital form that can be stored on the disc.
These images can be edited before they are printed.