Input Devices(इनपुट डिवाइस ) Input device enables the user to send data, information or control signals to computer. Central processing unit of computer receives the input and processes it to produce output. Some of the popular input devices are: Keyboard Mouse Scanner Joystick Light Pen Track ball Digitizer Microphone Magnetic Ink Character Recognition (MICR) Optical Character Reader (OCR) Keyboard (कीबोर्ड ) It is a basic input device that is used to enter data by pressing keys. It has different sets of keys for letters, numbers, characters and functions. QWERTY keyboard is the commonly used keyboard to enter data. Mouse (माउस) It is a hand held input device. It is used to move cursor or pointer across the screen. It generally has left and right button and a scroll wheel between them. Laptop computers come with a touch pad that works as a mouse. It lets you control the movement of cursor or pointer by moving your finger over the touchpad. Scanner (...