Chapter 2: Storage Devices

Chapter 2: Storage Devices

1. Storage devices are hardware components that store data in an electronic format that can be accessed at a later time

   • Non-volatile memory because when the computer is turned off, the data is kept.
   • Volatile memory is the RAM (Random Access Memory) and CACHE memory which is used to store data that is being processed
   • Storage media are the actual items that data is stored on. On the other hand, storage devices are the equipment that is used to store data onto media.
     • Example: Storage Media- Hard disk or Flash Memory
     • Example: Storage data- Hard Disks and USB Sticks

2. Hard Disk

   • Data is written to them by changing the magnetic state of tracks and sectors on the disk.
   • Susceptible to damage easily
   • Store large amounds of data and has fast data transfer rates
   • Require a power source

3. Optical memory

   • Portable discs that are written to and read from using laser technology
   • Include: CDs (Compact disc), DVDs (digital versatile disc) and BDs (Blu-Ray Disc)
   • CDs used for storing and sistributing music, whereas DVDs and BDs are used for storing and distributing movies
   • Optical memory can also be used for backing up data and sharing large files with other users.
   • Low cost of discs, their durable and their capacity
   • Recordable discs are therefore useful for one-off backups of data whereas rewritable discs are more useful when the data being backed up changes regularly.

4. Tape

   • Used for storing backups and archives
   • Unsuitable for data that needs to be accessed immediately
     • However, archives do not need to be accessed very often, and therefore this type of data that needs to be accessed immediately
   • Tape is very cheap compared to other storage methods

5. Flash Memory

   • Used in digital cameras, video cameras, mobile phones and USBs
   • Small and unlikely to get damaged
   • Useful when transferring data due to its cost
   • Do not require a constant power source unlike hard disks

6. Justifying choice of storage media:

   • Purpose
   • Capacity
   • Speed