DVD ("Digital Versatile Disc", once "Digital Video Disc", and now, officially standing for nothing according to DVD Demystified) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. DVDs resemble compact discs as their physical dimensions are the same (120 mm (4.72 inches) or occasionally 80 mm (3.15 inches) in diameter) but they are encoded in a different format and at a much higher density.

 A Brief History of DVD
When the media compares the current competition between two groups of manufacturers for the next, fourth generation, era of blue laser videodisc, to the Beta-VHS rivalry of videotape, it is an oversimplification that we cringe at. Every generation has had a format competition. If it did not, it would not be promising.

Generation one, the laser videodisc, competed with the RCA SelectaVision CED videodisc in the latter 1970's. Laserdisc won, but lost the battle for the prerecorded home video format to the videotape winner, VHS. Still, many videophiles collected the many films and music videos released on videodisc throughout the next twenty years. Pioneer, Sony, and Philips competed for the player market. The laser videodisc was the first computer peripheral to use mass replicated optical media up until the introduction of CD-ROM, and the first AV playback device to incorporate ROM-based programs for standalone interactivity.

Generation two, the compact disc, was more advanced in that it was digitally encoded and small enough to be rack mounted in a PC, car dashboard, boombox or portable music player. Philips headed off a threatened challenge by inviting Sony to share the patent pool and help convince the other Japanese consumer electronics companies with digital audio R&D to join the licensing program rather than enter the market. After CD-Audio, the pair had successful markets with CD-ROM multimedia PC, CD-ROM videogame console, and CD-R/RW. Ironically, the compact disc standard had only modest success with the two versions Generation One pioneered: prerecorded home video version, Video CD, and the standalone programmable CD-Interactive had modest success.

Generation three, the digital video disc, also had two fierce format warriors. Toshiba and Time Warner pushed prerecorded DVD on the market before there was a recordable version, preempting Philips and Sony from doing the same as an upgrade of their CD patents called MMCD a year or two later. Predictably, Toshiba had a better spec and a market head-start. But they did not have two things: a recordable version that would have made the elimination of the VCR a done deal for another 3 years, and a high density version that could carry a native HDTV signal. These would prove to be the Achilles Heel of DVD.

DVD-Video sold really well. The movie studios rose to the occasion and crafted good looking products with lots of extra goodies. But the other three content groups, games, music and publishing, didn't fare so well. The Playstation II and the XBox added DVD movie playback at the 11th hour and Nintendo never bothered to make the GameCube discs compatible. Cross-compatibility was never even discussed between the TV set-top console makers. The music version, as discussed, was about as big a mess-up as one could imagine.

DVD-ROM, the one version Infotech forecasted at the time would be the leading light following on the heals of CD-ROM multimedia, many of whose most popular programs were already spanning multiple discs, went nowhere. The multimedia producers were highly leveraged as the first group to attract venture capital for intellectual property, and in overdrive when the World Wide Web stole their thunder. They just didn't have any juice for a come back on DVD-ROM, and instead, playing DVD movies on your PC was the trigger for DVD-ROM drives to become PC peripherals. We ate that forecast.

DVD did not follow the game plan executed by Philips and Sony to build on the stunning success of CD with variations for every content segment. As a result, the combined sales of DVD-Video with DVD-Audio, DVD-ROM, and DVD-RW will not come near the record set by the CD formats, CD-Audio, CD-ROM, and CD-RW.

After a lifespan of ten years, during which time the capacity of hard disks increased a hundred-fold, the CD-ROM finally got the facelift it required to take it into the next century when a standard for DVD, initially called digital video disc but eventually known as digital versatile disc, was finally agreed during 1996.

The movie companies immediately saw a big CD as a way of stimulating the video market, producing better quality sound and pictures on a disc that costs considerably less to produce than a VHS tape. Using MPEG-2 video compression, the same system that will be used for digital TV, satellite and cable transmissions, it is quite possible to fit a full-length movie onto one side of a DVD disc. The picture quality is as good as live TV and the DVD-Video disc can carry multi-channel digital sound.

For computer users, however, DVD means more than just movies, and whilst DVD-Video grabbed most of the early headlines, it was through the sale of DVD-ROM drives that the format made a bigger immediate impact in the marketplace. In the late-1990s computer-based DVD drives outsold home DVD-Video machines by a ratio of at least 5:1 and, thanks to the enthusiastic backing of the computer industry in general and the CD-ROM drive manufacturers in particular, by early in the new millennium there were more DVD-ROM drives in use than CD-ROM drives.

Initially, the principal application to make use of DVD's greater capacity has been movies. However, the need for more capacity in the computer world is obvious to anyone who already has multi-CD games and software packages. With modern-day programs fast outgrowing CD, the prospect of a return to the multiple disc sets which had appeared to gone away for ever when CD-ROM took over from floppy disc was looming ever closer. The unprecedented storage capacity provided by DVD lets application vendors fit multiple CD titles (phone databases, map programs, encyclopaedias) on a single disc, making them more convenient to use. Developers of edutainment and reference titles are also free to use video and audio clips more liberally. And game developers can script interactive games with full-motion video and surround-sound audio with less fear of running out of space.