System Storage

System Storage

1. Secondary Storage

   • Three Types of Storage
     • Optical
       • When data is recorded by marking patterns on a disk with a laser light. Patterns can be translated and read again with said laser light. Non-Volatile e.g. DVDs , CDs
         • Encodes bits in the form of Pits (A 0 or off, due to lack of reflection when read) and Lands (A 1 or on, due to a reflection when read)
         • Benefits- Portable and Durable, quite Cheap, not Expensive
     • Magnetic
       • When data is stored by using different patterns of magnetization in a magnetizable material to store data. Non-Volatile e.g. Hard Drive, Floppy Disk
         • One pattern/level of magnetism will be a 1, the second will be a 0
         • Has a large Capacity, can be Fast and Reliable, very Cheap
     • Solid State
       • Made out of Microchips (Switches) which store data electronically. Non-Volatile e.g. SD Cards, Memory Cards
         • The state of the switches determine whether a 1 or a 0 is stored
         • Benefits-Very Fast, Portable, Reliable, Durable, very Expensive
   • Secondary Storage is needed so there so data can be accessed later, to use software and interact with the computer. Without it, software would have to be installed every time we use it and no files, data, photos or videos etc. could be saved

2. The 6 characteristics of secondary storage devices

   • Speed - How fats it can read and write data
   • Durability - How long it can last
   • Reliability - No changes in formating
   • Cost - How much it is worth (cheap or expensive)
   • Capacity - How much data there is.
   • Portability - If it can be transferred easily