Secondary Storage

• 2 tiers of storage

  • Primary storage 
  • Secondary storage
• Examples of Primary storage

  • RAM 
  • ROM 
  • Registers 
  • Cache

  
• What is Secondary storage

  • Secondary storage is where all data (And operating systems , programs , applications and user files) are held when they are not in  use 
  • Secondary storage has slow read/write speeds 
  • Secondary storage is non-volatile 
  • Secondary storage has a large storage capacity compared to primary storage
• What is Primary storage

  • Primary storage refers to the memory areas that the CPU can access very quickly 
  • Primary storage has fast read/write speeds 
  • Primary storage is mostly volatile , with the exception of ROM 
  • Primary storage has a small storage capacity compared to secondary storage
• Examples of Secondary Storage

  • Hard disk drives (HDDs) 
  • Solid State Drives (SSDs) 
  • Optical Discs 
  • Magnetic tapes 
  • Memory cards

  
• What Primary and Secondary storage are measured in

  • Primary Storage is measured in gigabytes (GB) 
  • Secondary Storage is measured in terabytes (TB)
• Tertiary storage

  • Tertiary storage is used for long term data storage 
  • Its mainly used for archives and back-ups of massive amounts of data
• Why Secondary Storage is needed

  • Because the memory in a computer system is either ROM - which is read-only and cannot be change 
  • Or RAM - which is volatile , and is lost when the power is switched of
• Why back ups are kept in Tertiary Storage

  Back ups are kept in case the main data file is lost or corrupt
• What are archives

  Archives are data that are moved from the main file to free up space