DigitalStorage

Measuring Memory and StorageTerm Abbreviatio

nApproximate Memory Size

Kilobyte KB or K =1000 bytes (actual size is 1024 bytes)

Megabyte

MB =1 million bytes

Gigabyte GB =1 billion bytes

Terabyte TB =1 trillion bytes

Methods of Storage

Magnetic

Flash

Optical

Magnetic Storage

Storage device that codes data as microscopic magnetized needles on the disk's surface The hard disk is the most common magnetic

storage deviceStorage capacity--terabytes

Flash StorageA type of constantly-powered

memory that can be erased and reprogrammed in a single action or “flash.”

Described as “solid-state” memory because there are no mechanical (moving) parts.

Examples: flash drives, camera storage cards

Some computers have a solid-state drive instead of the typical magnetic hard drive

Optical Storage

Storage device that records data by burning microscopic holes in the surface of the disk with a laser Compact disksDigital video disksBlu-ray disks

Compact DiskStandard storage capacity: 650-

700 MB

Three types: CD-ROM—permanent storage (650MB)CD-R—recordable but cannot be erased (700MB)CD-RW—recordable but can be changed (700MB)

Digital Video DiskStandard storage capacity--

4.7GB; there are formats that will hold at least double that

There are three basic types, although others are available:DVD-ROM—permanent storage, 17GBDVD±R—recordable, 4.7GB DVD±RW—recordable, but not erasable, 4.7GB

Blu-ray Disk

High capacity optical disk that has a storage capacity of 25GB.

Has recordable and rewritable disks just like CDs and DVDs.

Declining in popularity due to the increase in streaming video options