Should this happen then the information can be recovered by restoring or copying the information back from the backup. See magnetic tape. For a complete summary of tape, disk and optical storage technologies, see storage. A sequential storage medium used for data collection, backup and historical purposes. Like videotape, computer tape is made of flexible plastic with one side coated with a ferromagnetic material.
Tapes come in reels and cartridges of many sizes and shapes.
Although still used in legacy systems, open reels have been mostly superseded by cartridges with enhanced storage capacities. Locating a specific record on tape requires reading every record in front of it or searching for markers that identify predefined partitions. Although most tapes are used for archiving rather than routine updating, some drives allow rewriting in place if the byte count does not change. Over the years, storage density has increased from 200 to 38,000 bpi. Tape is more economical than disks for archival data.