1.3 Storage

1.3 Storage

1. Secondary Storage

   • A non-volatile storage medium which stores files and programs.
     • Examples include: Hard drive, Solid state drives

2. Magnetic devices

   • Magnetic disks are read and written to with a moving head inside the disk drive
   • Often contain moving parts and susceptible to damage

3. Solid state drives

   • No moving parts. It retains an electronic charge using logic gates.
     • Examples include: SD cards and USB memory sticks

4. Optical devices

   • Lasers are used to read and write data to a disk.
   • Examples include: DVD, CD and blu ray disks

5. Cloud storage

   • Cloud storage refers to saving data in an off-site location maintained by another party.
     • Examples include: Dropbox, Google and Microsoft
       • This relies on having internet connection to upload and download files from the cloud servers

6. Comparing Secondary storage

   • Capacity
     • The amount of space that is avalable for storing files. Generally measured in GB
   • Speed
     • How quickly a computer can read and write data from a storage device
   • Portability
     • How easy a device is to be transported
       • Some devices may be permanent others may not
   • Durability
     • Will the device withstand a certain amount of damage without corrupting files
   • Reliability
     • The length of time a device is meant to last for
   • Cost
     • How expensive an item is per GB or MB

7. What would happen without secondary storage?

   • WE would need to install the OS everytime we use the computer

8. Why do we store things?

   • To acesss them again later

9. Bit

   • Byte
     • KB
       • MB
         • GB
           • TB
             • TerraByte
             • PB
               • EB
                 • ZB
                   • YB
                     • YottaByte
                   • ZettaByte
                 • ExaByte
               • PetaByte
           • GigaByte
         • MegaByte
       • KiloByte

10. Types of storage

    • Optical
    • Magnetic
    • Solid state

11. 1 Byte = 8 Bits

    • 1KB = 8000 bits
      • 1MB = 8000000 bits

12. 1000KB in a MB

    • 1000MB in a GB
      • 1000 GB in a TB