Storage

Storage
Storage refers to the media either data are storage temporarily or permanently. There are two main types of storage.
Primary Storage or main Memory 
Secondary Storage 
Primary Storage or main Memory (RAM)
Primary storage,presently known as memory or simply RAM,is the only one directly accessible to the CPU.The CPU continuously reads instruction stored there and executes them as required.

• Operating system and other system software that controls or maintain the computer and its devices.
• Application program that carry out a specific task such as word processing etc.
• Data to be processed by the a application programs and resulting information.

RAM

RAM stand for Random Access Memory.RAM is also called main memory or primary storage, it consists of memory chips that can and written to by the processor and other devices. RAM varies in size like 128 MB,256 MB And 512 MB to 2 GB.RAM cannot data and instruction permanently.When we switch off the computer,all data and instruction from RAM are washed or vanished.Therefor it is called volatile memory.

ROM

ROM stand for Read Only Memory.it consists of those instruction that prepare the computer for use.ROM instruction are automatically load into the main Memory.These instruction can only be read but cannot be changed or deleted.it is not possible to write new instruction into the ROM.it store data and Instruction permanently.When we switch off the computer,the instructions stored in the ROM are not lost. Therefore it is a non-volatile memory.