optical storage is a method of reading and writing data when using laser
- discs
-DVD
-blu -ray
- discs
-DVD
-blu -ray
magnetic storage
media and devices store data in the form of magnetised dots.
examples :
-hard disk drive
- portable hard disk drive
- magnetic taypes
media and devices store data in the form of magnetised dots.
examples :
-hard disk drive
- portable hard disk drive
- magnetic taypes
solid state storage
no moving parts no reels of tape ,no spinning discs no laser beams
example
- memory sticks
-flash memory cards
no moving parts no reels of tape ,no spinning discs no laser beams
example
- memory sticks
-flash memory cards
back up
- a back up is a copy of a file .
-it is stored on an alternative medium to the original.
- data could be corrupted on the original medium.
- data could be accidentally or maliciously deleted/amended from the original medium.
- a back up is a copy of a file .
-it is stored on an alternative medium to the original.
- data could be corrupted on the original medium.
- data could be accidentally or maliciously deleted/amended from the original medium.
storage methods
there are two main storage method one is sequential and random access.
sequential
data is storage in a que to find it you would have to go through all your back up storage
disadvantages :
- takes a long time
advantages :
- store a long amount of data
- cheaper
- magnetic tape
there are two main storage method one is sequential and random access.
sequential
data is storage in a que to find it you would have to go through all your back up storage
disadvantages :
- takes a long time
advantages :
- store a long amount of data
- cheaper
- magnetic tape
random / direct access
were you can go directly to the data and skip all the rest
advantages :
- quicker
disadvantages :
-cost more
were you can go directly to the data and skip all the rest
advantages :
- quicker
disadvantages :
-cost more