The Nitty-Gritty:

Q: Why So Many DVD Formats?

A: The crucial difference among DVD standards is based on which standards each manufacturer adheres to. Similar to the old VHS/Beta tape wars when VCRs first hit the markets, different manufacturers support different standards. Often called a 'format war', both the industry and consumers are still waiting to see which format will emerge as the industry standard.

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Q: Plus or Minus - What's The Difference?

A: The different variations on the term DVD (e.g. +R, -R, -ROM, and so on) describe the way data is stored on or written to the disc itself. These are called physical formats.

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Q: What's the different types?

A:

• DVD+R and DVD+RW

DVD+R and DVD+RW formats are supported by Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha and others.

DVD+R is a recordable DVD format similar to CD-R. A DVD+R can record data only once and then the data becomes permanent on the disc. The disc can not be recorded onto a second time.

DVD+RW is a re-recordable format similar to CD-RW. The data on a DVD+RW disc can be erased and recorded over numerous times without damaging the medium.

Note: DVDs that have been made using a +R/+RW device can be read by most commercial DVD-ROM players.

• DVD-R, DVD-RW and DVD-RAM

These formats are supported by Panasonic, Toshiba, Apple Computer, Hitachi, NEC, Pioneer, Samsung and Sharp. These formats are also supported by the DVD Forum.

• DVD+R DL and DVD-R DL

Dual layer technology is supported by a range of manufacturers including Dell, HP, Verbatim, Philips, Sony, Yamaha and others. As the name suggests, dual layer technology provides two individual recordable layers on a single-sided DVD disc. Dual Layer is more commonly called Double Layer in the consumer market, and can be seen written as DVD+R DL or DVD-R DL.

• DVD Burners

Until 2003 consumers would have to choose a preferred DVD format and purchase the DVD disks that were compatible with the DVD burner. In 2003, Sony introduced a multi-format DVD burner (also called a combo drive or DVD-Multi) and today many manufacturers offer multi-format DVD burners that are compatible with multiple DVD formats (as listed above).

• HD-DVD

Short for high definition-DVD, a generic term for the technology of recording high-definition video on a DVD. In general, HD-DVD is capable of storing between two and four times as much data as standard DVD.

On February 19, 2008, Toshiba issued a release stating that it would no longer develop, manufacture and market HD DVD players and recorders, with cessation of the player and recorders targeted for March 2008. Several major retail chains, such as Wal-Mart followed with plans to no longer carry the product, and major Hollywood studios have also dropped plans to release product in HD-DVD format as well.

• Blu-ray Disc (BD)

Uses a 405nm-wavelength blue-violet laser technology, in contrast to the 650nm-wavelength red laser technology used in traditional DVD formats. The rewritable Blu-ray disc, with a data transfer rate of 36Mbps (1x speed) can hold up to 25GB of data on a single-layer disc and 50GB on a dual-layer disc. On a 50GB disc, this translates into 9 hours of high-definition (HD) video or approximately 23 hours of standard-definition (SD) video. The Blu-ray format was developed jointly by Sony, Samsung, Sharp, Thomson, Hitachi, Matsushita, Pioneer and Philips, Mistubishi and LG Electronics.

• Advanced Optical Disc (AOD)

AOD and Blu-ray are similar in that they both use 405nm-wavelength blue-violet laser technology. While Blu-ray has a storage capacity of 25GB on a single-layer disc, AOD has a storage capacity of 20GB on a single-layer disc. and the capacity to hold 30GB on a dual-layer disc. AOD was developed jointly by Toshiba and NEC.

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Q: What are the different media types?

A:

• DVD-5

Currently the most common DVD media available to consumers, DVD-5 is a single-sided, single layer DVD that can hold up to 4.7GB (120 minutes) of data. All DVDs are made from two substrates that are bonded together, and the second substrate on a DVD-5 is a data-less layer.

• DVD-9

A single-sided dual-layer DVD disc, DVD-9 can hold approximately 8.5GB of data. It should be noted that DVD-RW and DVD+RW do not support DVD9.

• DVD-10

DVD-10 are double sided, single layer discs. The kind where part of the movie is on one side of the disc, and the rest of the movie on the other. (Or Widescreen version on one side, Full Frame on the other).

• DVD-18

DVD-18 is a double sided dual layer DVD which can fit up to 17 GB or 15.9 computer GB which some commercial video DVDs are using today. (A DVD-18 is basically four pressed plastic DVD-5s pressed together.) Video DVD supports this format but DVD-R/W and DVD+R/W does not support this format.