Digital Storage

Measuring Memory and Storage TermAbbreviationApproximate Memory Size KilobyteKB or K=1000 bytes (actual size is 1024 bytes) MegabyteMB=1 million bytes GigabyteGB=1 billion bytes TerabyteTB=1 trillion bytes

Methods of Storage Magnetic Flash Optical

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

Flash Storage A 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.  Also known as a pen drive, thumb drive, jump drive.  Storage cards for digital cameras use flash memory.

Optical Storage Storage device that records data by burning microscopic holes in the surface of the disk with a laser  Compact disks Compact disks  Digital video disks  Blu-ray disks

Compact Disk CD-ROM: stores information permanently; cannot be changed; typical media used for software ; 650MB capacity CD-R: recordable; can record multiple times but cannot be erased or overwritten; MB capacity CD-RW: rewritable; can store, erase, and replace data information like a floppy disk or hard drive; 700 MB capacity is typical.

Digital Video Disk DVD-ROM—typical storage capacity 17GB; permanent storage DVD-R, DVD+R, DVD±R—recordable, can record multiple times but cannot be erased or overwritten; 4.7 GB capacity DVD-RW, DVD+RW, DVD±RW—can store, erase, and replace data information like a floppy disk or hard drive; 4.7 GB capacity is typical.

Blu-ray Disk High capacity optical disk that has a storage capacity of 25GB. Has recordable and rewritable disks just like CDs and DVDs. How Blu-ray Discs Work