Write Once Read Many
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Write Once, Read Many (alternatively Write One, Read Multiple, or WORM) refers to a kind of computer storage media that can be written to once, but read from multiple times.
There are two types of WORM storage media: those that physically can be written only once (examples of such storage media are CD-R and DVD-R, or electronic circuits such as PROMs) and media that enables WORM capability by using electronic keys or other measures to prevent rewriting. The reasoning behind this artificial hampering of technical capability in the latter case can be found in regulatory authorities requiring certain data archival standards where information has to be reliably kept and made available over a long period of time (an example would be the Securities Exchange Commission).
Media which intentionally restricts writing to one time only: Super DLT (Super DLT II media is in fact used for standard and WORM operations, as demanded by the user), LTO, AIT and various hard disk drive based systems. Software write protection is less secure and some of these systems actually enable recycling of pre-used media.
