REGISTERS

A processor register is a small amount of storage available as part of a CPU or other digital processor.
it is for

• special purpose
• high speed
• temporary storage

                      MAIN MEMORY

there a two types of memory
       RAM (random access memory)
       ROM ( read only memory)
  
                   RANDOM ACCESS MEMORY

the term random access means that any word in the memory may be accessed, without having to go through all the other words to get it. this memory is an integrated circuit chip.
RAM has two types

• DRAM
• SRAM

              READ ONLY MEMORY

ROM chip is installed by the manufacturer inside the computer. its also called firmwire, it retains instructions in a permanently accecible non volatile form. when the power in the computer is turned off, the instructions stored in ROM are  not lost.