magnetic disk & tape

The primary computer storage media. The choice depends on accessing requirements. Disk is direct; tape is sequential. Locating a program or data on disk takes a fraction of a second. On tape, it can take several seconds or even minutes.

Tapes have traditionally been used for backup and archival storage, and tape libraries with robotic mechanisms are common in large enterprises. For a while, single tape drives were popular for desktop computers, but were eclipsed by Zip disks, CD-Rs, CD-RWS and other removable magnetic disk media (see Jaz and ORB).

In time, magnetic media may be as obsolete as punch cards. Optical technologies, or perhaps some other yet-to-be-known derivative, that employ no moving parts should eventually supersede them. Considering the magical technology within the chip, moving chunks of metal and plastic past a read/write head seems archaic by comparison. See magnetic disk, magnetic tape, optical disc and HSM.