Secondary storage

• Types of Secondary Storage

  • Optical
  • Magnetic
  • Solid State
• Optical Storage


  • Uses a laser shone at the surface of the disc, and then processing the reflection from the disc
  • Optical Storages are discs, and examples are CDs, DVDs, and Blu-Rays
• Magnetic Storage


  • Data is stored via magnetised dots
  • Often has moving parts
  • Examples are Hard Disc Drive (HDD) and Floppy Disk (no longer used due to poor durability and reliability)
• Solid State Storage


  • Data is stored via electricity
  • Becoming increasingly popular as its capacity increases and cost decreases
  • Examples are Memory Sticks, SSDs, and SD Cards
• Solid State Drives (SSDs) use flash memory to store data and have no moving parts.
• The main advantage of magnetic tape is its low cost.
• Magnetic tapes are used to store large amounts of data, such as backups or archives.
• Flash Memory uses NAND gates to store information using transistors that can be switched on or off.
• Hard drives are used as secondary storage devices because they can hold large amounts of data and have fast access times compared to other types of storage media.
• Optical disks use laser beams to read and write information on the disk surface.
• Magnetic tapes are not commonly used anymore because they are slow compared to other forms of secondary storage.
• Secondary Storage


  Where we store data for longer than just whilst the computer is turned on
• Secondary Storage


  • It is not volatile
  • Data remains even after the power has been turned off
• We can save our programs and files on Secondary Storage, turn off our device, and the next time we turn our device back on, we won't have lost them
• Purpose of Secondary Storage

  It allows us to store programs and files when they are not in use, as well as whilst the power has been turned off