Following are few of the important input devices which are used in a computer:

• Keyboard
• Mouse
• Joy Stick
• Light pen
• Track Ball
• Scanner
• Graphic Tablet
• Microphone
• Magnetic Ink Card Reader(
• Optical Character Reader(OCR)
• Bar Code Reader
• Optical Mark Reader 

Keyboard

The keyboard is the most common and popular input device, it can help in entering data into the computer. The keyboard layout is such a traditional typewriter, although providing additional functionality to perform some additional keys are used.

84-key keyboard in two sizes or 101/102 key, but now 02-11-22104 keys or 108 keys are also available for Windows and the Internet.

The mouse is the most popular pointing device. It is has a round ball at its base, it detects the movement of the mouse, and sends a corresponding signal, CPU when the mouse button is pressed a small palm-sized box of a very famous cursor control device.

Usually it has two buttons called the left and right buttons, a wheel between this button. Mouse can be used to control the position of the cursor on the screen, but it can not be used to enter text into the computer.

The joystick is also used to move the cursor position on the monitor screen to indicate the device. It is a rod having a spherical ball at its two lower and upper ends. The lower spherical ball in the socket move. You can move the joystick in all four directions.

Joystick function is similar to a mouse. It is mainly used for computer-aided design (CAD) and playing computer games.