Did you know

1. The official DVD specification is maintained by the DVD Forum, formerly the DVD Consortium, consisting of the ten founding companies and over 220 additional members. The first DVD players and discs were available in November 1996 in Japan, March 1997 in the United States, 1998 in Europe and in 1999 in Australia.

2. Compact discs are made from a 1.2 mm thick disc of polycarbonate plastic coated with a much thinner layer of super purity aluminium (or rarely, gold, used for its data longevity, such as in some limited-edition audiophile CDs) which is protected by a film of lacquer. The lacquer can be printed with a label. Common printing methods for compact discs are silkscreening and offset printing. CDs are available in two sizes. By far the most common is 120 mm in diameter, with a 74-minute audio capacity and a 650-MB data (See storage capacity; this form factor has also erroneously been called "CD5" since it is about five inches across). Such a standard disc weighs 15 grams. They are also available as 80-mm discs, a format which is mainly used for audio CD singles in some regions (e.g. Japan), much like the old vinyl single. Each such "miniCD" or "Maxi CD" can hold 21 minutes of music, or 180 MB of data (this form factor has also been called "CD3", since it is about three inches across). Other unique shapes and smaller form factors have also been sold or given away as promotional items. Examples include Business Card CDs in the shape of a rectangular card, CDs shaped like the map of a country, etc.