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Bars are codes that represent different numbers. One can see the bar code on the back cover of this book
                 as well. A bar code reader emits a beam of light (Laser Beam), which reflects the bar code image. A light
                 sensitive detector is present in the bar code reader which identifies and reads the bar code image. The
                 bar pattern is changed into numeric code inside the CPU.



                              Microphone

                              A microphone is a voice based input device. With the help of this device, sound or voice
                              is recognized/recorded in the computer and is converted into digital form which is then
                              played or processed by the computer.






                 Digital Camera

                 A digital camera  captures  image or  picture  momentarily  and  converts
                 the image directly into digital form and stores in memory. It can then be
                 viewed on the computer or compatible devices.

                 It is available in various models with different specifications that include
                 pixels, sizes and memory. The quality of image captured by digital camera
                 is measured in pixels.


                                   Web Camera

                                   A web camera or a webcam is a type of video camera that captures images or visuals
                                   in real-time & passes data to a computer via USB, ethernet or Wi-Fi. Web cam do not
                                   have an inbuilt storage like a digital camera.
                                   Web camera  is used to create  video links  and  allows set up of authentic  video-
                                   conference  stations.  Some built-in webcams  can  be remotely  activated  from far
                                   off  locations.  Webcams can  also be  used  for  security  & surveillance  purposes  by
                                   monitoring the captured visuals.


                 Biometric Devices

                 These devices use the physical characteristics of a living being to authenticate
                 its identity. These devices are capable of scanning hand prints, finger prints,
                 retinal information, facial features etc. to compare with a sample and grant
                 access to an individual to a particular device or information. Example: Used in
                 phones for security and used for attendance tracking in offices.

                           Notes

                           Biometric  Sensor  is  a  device  which  captures  unique  information  from  human  body.  The  unique
                           information can be fingerprints, iris pattern, etc. It stores and compares to match the information
                           with the available database.




                                                                             Basics of Information Technology    17
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