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Light Pen
                      A light pen is a pointing device shaped like a pen and is connected to a VDU. The tip of the light pen
                      contains a light-sensitive element which, when placed against the screen, detects the light from the
                      screen enabling the computer to identify the location of the pen on the screen. We generally use it to
          Light Pen   make a selection or draw anything on a screen.

        Touchscreen

        Touchscreen is the latest in the input devices where the input can be taken from the
        user through a touch of a finger, stylus or a light pen on a display screen. We can
        give the entire set of commands by touching. Nowadays most of the laptops, Smart
        TV, smartphones, tablets, etc. also have touch screens where the use of the keyboard
        is minimised. It is a very useful and convenient alternative to a mouse or a keyboard
        in a graphical user interface.                                                        Touchscreen

                          Microphone

                          Microphone is a device that converts the sound received into a digital audio form which can be
                          easily stored or manipulated in a computer.
           Microphone
        Barcode Reader

        A bar code is a set of parallel lines that appear on the products as their identification.
        You will find most of the packages having these barcodes that can be easily read by
        barcode readers. Bar code readers work by placing a beam of light on the lines that
        make up the bar code and detecting the amount of light that is reflected back. The
        barcode read is then stored in the computer for preparing invoices.                   Barcode Reader


        MICR

        The bank account number and other details are printed onto bank cheques which are
        read by Magnetic Ink Character Recognition using a special magnetic ink. They are useful
        to find out whether the cheque is genuine or fake.

                                                                                                   MICR
                PROCESSING DEVICE CENTRAL PROCESSING UNIT (CPU)

        After taking the input from the input devices, the information is sent for processing. The computer uses its brain to
        process the information. The computer’s brain is called the CPU or Central Processing Unit. CPU is basically divided into
        three parts:
                               •   ALU stands  for  Arithmetic  Logic  Unit. It is responsible  for all  arithmetical and logical
                                 calculations.
                               •   CU stands for Control Unit. It controls the flow of information in the system. The control
                                 unit is responsible for the flow of data from input devices to the processing unit and then
                                 to the output devices. It works like a traffic policeman who controls the traffic on the road.
                               •   MU stands for Memory Unit. It is a storage unit that holds the processed or unprocessed
              CPU Chip           data.






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