Editing Computer data storage (section)

=== Optical ===
{{Optical storage media}}

[[Optical storage]], the typical [[optical disc]], stores information in deformities on the surface of a circular disc and reads this information by illuminating the surface with a [[laser diode]] and observing the reflection. Optical disc storage is ''non-volatile''. The deformities may be permanent (read only media), formed once (write once media) or reversible (recordable or read/write media). The following forms are in common use {{As of|2009|lc=true}}:<ref>{{Cite web|url=http://www.dvddemystified.com/dvdfaq.html|title=The DVD FAQ - A comprehensive reference of DVD technologies|archive-url=https://web.archive.org/web/20090822172353/http://www.dvddemystified.com/dvdfaq.html|archive-date=22 August 2009}}</ref>

* [[CD]], [[CD-ROM]], [[DVD]], [[BD-ROM]]: Read only storage, used for mass distribution of digital information (music, video, computer programs);
* [[CD-R]], [[DVD-R]], [[DVD+R]], [[BD-R]]: Write once storage, used for tertiary and off-line storage;
* [[CD-RW]], [[DVD-RW]], [[DVD+RW]], [[DVD-RAM]], [[BD-RE]]: Slow write, fast read storage, used for tertiary and off-line storage;
* [[Ultra Density Optical]] or UDO is similar in capacity to [[Blu-ray Disc recordable|BD-R or BD-RE]] and is slow write, fast read storage used for tertiary and off-line storage.

[[Magneto-optical drive|Magneto-optical disc storage]] is optical disc storage where the magnetic state on a [[ferromagnetic]] surface stores information. The information is read optically and written by combining magnetic and optical methods. Magneto-optical disc storage is ''non-volatile'', ''sequential access'', slow write, fast read storage used for tertiary and off-line storage.

[[3D optical data storage]] has also been proposed.

Light induced magnetization melting in magnetic photoconductors has also been proposed for high-speed low-energy consumption magneto-optical storage.<ref name="Náfrádi 2016">{{cite journal|last1=Náfrádi|first1=Bálint|title=Optically switched magnetism in photovoltaic perovskite CH3NH3(Mn:Pb)I3|journal=Nature Communications|date=24 November 2016|volume=7|page=13406|doi=10.1038/ncomms13406|pmc=5123013|pmid=27882917|bibcode=2016NatCo...713406N|arxiv=1611.08205}}</ref>