1.2.2 Secondary Storage

• Secondary Storage


  Needed to store files and programs

  Needs to be non-volatile, low cost, high capacity and reliable
• Magnetic Storage


  Mostly uses hard disk drives (HDDs)

  Made of stack of magnetic disks or platters that rotate

  A moving read/write head moved across the surface of the platter to read and write data

  Reliable and cost effective and provide high capacity storage at low cost
• Solid-state Storage


  Uses technology called flash memory

  Used in portable hand-held devices

  In form of solid-state drives (SSDs)

  No moving parts means access to data is faster

  No moving parts also mean low and no noise or heat is generated

  More Robust

  Lightweight

  Compact
• Optical Storage


  Devices that use the properties of light to store data

  Optical disks - CSs, DVDs and Blu-Ray