DVD
The DVD (common abbreviation for Digital Video Disc or Digital Versatile Disc)[9][10] is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kind of digital data and has been widely used to store video programs (watched using DVD players), software and other computer files. DVDs offer significantly higher storage capacity than compact discs (CD) while having the same dimensions. A standard single-layer DVD can store up to 4.7 GB of data, a dual-layer DVD up to 8.5 GB. Variants can store up to a maximum of 17.08 GB.[11]
This article is about the disc format in general. For the video recording format based upon DVD, see DVD-Video. For the audio storage format also based upon DVD, see DVD-Audio. For other uses, see DVD (disambiguation).Media type
DVD-ROM and DVD-R(W) use one encoding, DVD-RAM and DVD+R(W) uses another
4.7 GB (single-sided, single-layer – common)
8.5 GB (single-sided, double-layer)
9.4 GB (double-sided, single-layer)
17.08 GB (double-sided, double-layer)
Up to four layers are possible in a standard form DVD.
300–650 nm laser, 10.5 Mbit/s (1×)
650 nm laser with a focused beam using more power than for reading, 10.5 Mbit/s (1×)
Diameter: 12 cm (4.7 in)
Thickness: 1.2 mm (0.047 in)
16 grams (0.56 oz)
Prerecorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are a form of DVD-ROM because data can only be read and not written or erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased many times.
DVDs are used in DVD-Video consumer digital video format and less commonly in DVD-Audio consumer digital audio format, as well as for authoring DVD discs written in a special AVCHD format to hold high definition material (often in conjunction with AVCHD format camcorders). DVDs containing other types of information may be referred to as DVD data discs.
Etymology
The Oxford English Dictionary comments that, "In 1995, rival manufacturers of the product initially named digital video disc agreed that, in order to emphasize the flexibility of the format for multimedia applications, the preferred abbreviation DVD would be understood to denote digital versatile disc." The OED also states that in 1995, "The companies said the official name of the format will simply be DVD. Toshiba had been using the name 'digital video disc', but that was switched to 'digital versatile disc' after computer companies complained that it left out their applications."[12]
"Digital versatile disc" is the explanation provided in a DVD Forum Primer from 2000[13] and in the DVD Forum's mission statement, which the purpose is to promote broad acceptance of DVD products on technology, across entertainment, and other industries.[14]
Because DVDs became highly popular for the distribution of movies in the 2000s, the term DVD became popularly used in English as a noun to describe specifically a full-length movie released on the format; for example the sentence to "watch a DVD" describes watching a movie on DVD.[15]
