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Projector
                                       A projector is a display device that projects a computer screen onto a flat surface: like

                                       whiteboard or wall. It is most commonly used for home theaters or in organisations
                                       for official presentations.
                 Projector



                 COMPUTER MEMORY

        Computer memory holds raw data before it goes for processing and after processing it contains information which can
        either be sent to output devices or stored in secondary storage devices for future use. There are two types of memory
        in the computer— primary memory and secondary memory.

        Primary Memory

        This type of memory is necessary for a computer to work. It is also called the Internal Memory. This is the actual place
        where the data is stored before it is taken to ALU for processing. Primary memory is of two types: RAM and ROM.
        RAM (Random Access Memory)

        It is temporary in nature. The computer holds information in this memory and gets it
        when needed. It remembers what you  tell them and  can even change  to remember
        new information. It is volatile in nature, which means that data will be erased when
        the computer is turned off. That’s why you always save your work! RAM is considered
                                                                                           Random Access Memory
        “random access” because any part of it can be accessed randomly for reading or writing
        of the data.

                                 ROM (Read Only Memory)

                                 It is permanent in nature. It is non-volatile which means even after turning your computer
                                 off, the contents of ROM will remain. The information is coded at the time of manufacturing
                                 the computer. The computer needs this information for its basic functions.


          Read Only Memory
        Secondary Memory
        Secondary Memory provides extra storage where the data can be stored permanently for later use. It is also known
        as external memory as it can be stored anywhere. Examples of secondary memory are compact disc, hard disc, flash
        drive, etc.

        Hard Disk
        A Hard Disk stores and provides quick access to large amounts of data on an electromagnetically
        charged surface or set of surfaces. Hard disks are generally fitted inside the system unit.
        However, there are external hard disks also available. A hard disk is made-up of a collection
        of disks called platters stacked on a cylindrical rod. Each of which, like phonograph records,
        has  data  recorded  electromagnetically  in  concentric  circles  or  “tracks”  on  the  disk.  The
        capacity of a hard disk varies from a few Gigabytes to a few hundred Terabytes.            Hard Disk








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