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Memory receives instructions and data from the input devices and stores them till they are needed by
                 other parts of the computer. Once the instructions are executed, the results are transferred to a permanent
                 location which are then stored in a storage device.
                 Memory can be classified into two types:

                 l  Primary Memory                              l  Secondary Memory


                                                Memory and Storage Devices





                                Primary                                          Secondary


                                                                                                    Flash Memory
                                                             Magnetic              Optical
                                                                                                       storage
                      RAM                    ROM                                     CD                Flash drive
                                                             Hard disk

                                                                                    DVD              Flash memory


                                                                                 Blu-ray disc         Memory Stick


                 Primary Memory

                 Primary Memory is also known as Main Memory. It is that part of the CPU that stores the data and
                 instructions that are meant for current processing or for the internal management of the computer. It has
                 a limited capacity for storage of data.
                 Primary Memory can be classified into two groups:

                 l  RAM (Random Access Memory)             l  ROM (Read-Only Memory)

                 RAM
                 It holds the information temporarily, during the ongoing operation of a computer. When a computer is
                 under operation, the data or instructions come into its memory for instant access from the secondary
                 memory.  During  the  course of the  execution  of instructions,  some
                 intermediate results may be produced which are stored in the RAM.

                 RAM is a volatile memory i.e. when a computer is  switched OFF  or
                 the power supply is interrupted, all the information stored in it gets
                 disappeared or lost. RAM chip is made of Metal Oxide Semiconductor
                 (MOS). RAM is available in the form of chips of different capacities, E.g.,
                 4 GB, 8 GB, 16 GB, 32 GB, 64 GB, etc. You can upgrade the capacity of existing RAM in a computer by
                 installing extra RAM chips in addition to the existing ones. There are different types of RAM like SRAM,
                 DRAM, SDRAM, EDRAM, ECRAM, etc.








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