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Knowledge organisers / Secondary Storage

The need for secondary storage

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Knowledge organiser

Secondary Storage

1.2.2a

What you need to know

Secondary storage is needed because RAM is volatile — data is lost when the computer is turned off. Secondary storage provides non-volatile, long-term storage for files, programs, and the operating system.

Key points

  • Definition:Secondary Storage: non-volatile storage not directly accessible by the CPU, used for long-term data retention.
  • Data and files are retained when the computer is switched off because secondary storage is non-volatile.
  • Secondary storage is needed to store the operating system, applications, and user files permanently.
  • It is slower than primary storage (RAM) but has much larger capacity.
  • Exam Tip:The key reason for secondary storage is that RAM is VOLATILE — without secondary storage, all data would be lost every time the computer is turned off.
  • Definition:Secondary Storage: long-term, non-volatile storage of data/files. Also called external or auxiliary storage.
  • Common Mistake:Saying secondary storage is 'used when primary storage is full' — that describes virtual memory. Secondary storage is for PERMANENT/LONG-TERM data retention.
  • Exam Tip:When asked for a secondary storage DEVICE, give a specific device (e.g. 'hard disk drive', 'SSD', 'USB flash drive') — NOT a type (e.g. 'magnetic' or 'solid state').