Backing Storage
Solid State
USB flash drive
Used as portable storage
Capacity up to 64 Gb
Memory Card
Cost up to £100 depending on capacity
Used for portable devices eg. digital camera
Capacity up to 16 Gb
Fast to read and write to
Optical Disks
DVD - digital versatile disk
Capacity normally 4.7 Gb but up to 17 Gb
DVD-R
DVD-ROM
DVD-RW
CD - compact disk
Capacity up to 700 Megabytes
CD-ROM
Cannot be written to
CD-R
Can be written to once only
CD-RW
Can be written to again and again
Fast to read
Magnetic Tape
Cost up to £150 depending on capacity
Used for BACKUP (copies of files)
Slow to read and write to
Sequential Access
Magnetic Media
Floppy Disk
Cost approx 15p each
Portable
Small capcity
up to 1.44 Megabyte
Slow to access and write to
Hard Disk
Cost up to £200 depending on capacity
Can buy portable hard disks
Used for continuous, interactive access
Very large capacity
Up to 1 Terabyte
Very fast to read and write to
Random Access
Magnetic media
