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CD
                                  A compact disc is a small, portable, round disc made of molded polymer used for recording,
                                  storing  and  playing  back audio, video, text, and  other information  in  the digital  form.  It
                                  was originally developed to store sound recordings exclusively, but later it also allowed the
                                  preservation of other types of data. It stores data of low capacity upto 700 MB.

                  CD
            DVD
            Digital Versatile Disk is used for storing digital data using optical rays. It is the same size as a CD,
            but has a larger storage capacity. They are commonly used to store large volumes of data including
            audio and video files. It stores data upto 10 GB.
                                                                                                            DVD
                             Blue Ray Disc
                             Blue  Ray  Disc  is  of  the  same  dimension  as  that  of  CD  or  DVD  and  uses  the  same  optical  rays
                             technology for recording and playing back high-definition (HD) video and for storing large amounts
                             of data. It has a capacity of up to 25 GB.
             Blue Ray Disc


            Flash Drive
            Flash drive functions as a portable hard drive. It’s a small and portable memory card that plugs
            into a computer’s USB port. USB flash drives are smaller and more durable with large storage
            capacity. It can be used in any computer with USB port. USB flash drives are also called thumb
            drives, pen drives, key drives or simply USB drives. It stores data upto 2 TB.
                                                                                                        Flash Drive

                              Memory Stick
                              Memory stick is a portable memory card used as an add-on for smartphones, digital cameras,
                              SmartTV etc. its capacity varies from 4 GB to 128 GB.
              Memory Stick



                    MEASURING UNIT FOR MEMORY

            The measuring unit to measure our data stored in memory or storage devices is byte. Byte for a memory is just
            equivalent to kilometer for a distance or second for time or Kilogram for weight.
            Computers work in binary digits— 0 and 1 to form endless combinations of 8 bits(1 Byte). This byte represents a single
            letter, number, punctuation or any other special character on the keyboard. These bytes combine in different forms to
            represent data.
            •  Bit: A bit is the smallest measuring unit. It can be either 0(Off) or 1(On).
            •  Byte: A byte is the basic unit for measuring units. It is made up of 8 bits.
            To represent huge data we have different units to measure as listed below:

                                     1 Byte                      8 Bits

                                     1 Kilobyte (KB)             1024 Bytes
                                     1 Megabyte (MB)             1024 KB

                                     1 Gigabyte (GB)             1024 MB



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