Main memory

RAM, ROM and Backing storage

Main memory

  • Main memory is located inside the computer system, it can be either RAM or ROM
  • The average RAM capacity of today's computers is ~ 8 GB

Backing storage

  • Backing storage is located outside the main computer e.g. HDDs DVDs CDs etc.
  • Backing is has a far greater capacity, with average computers having ~ 1 TB

ROM (Read - Only memory)

  • ROM is used to store a small part of the operating system called the bootstrap loader
  • Data is stored permanently in ROM
  • Data on ROM is not lost when power is lost
  • Data stored on ROM cannot be changed

RAM (Random - Access memory)

  • This the where the operating system is loaded to on startup. RAM also holds all programs and data being used on the computer
  • The processor can read / write to RAM at high speeds
  • Data stored on RAM can be changed
  • All data stored on RAM is lost when power is lost (RAM is volatile memory)