The Main Memory

RAM & ROM

Main Memory

Main memory is located inside the computer system, it can either have RAM or ROM. Main memory in today’s computers is on average around 4-8 Gb of RAM.

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People often get confused with the main memory and backing storage, Backing storage is outside the main processor, e.g. Hard Drives, CD/DVD drives, USB Flash Memory (Pen Drives).

Difference Between RAM & ROM

RAM: ( RANDOM ACCESS MEMORY)


  • The processor can write to and read from RAM at high speed
  • Data held in RAM can be changed
  • All data in RAM is lost when the power is switched off.



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ROM: (READ ONLY MEMORY)


  • Data is stored permanently in ROM
  • Data is not lost when the power is switched off
  • Data in ROM cannot be changed