Blu-ray Disc (also known as Blu-ray or BD) is an optical disc storage media format. Its main uses are high-definition video and data storage. The disc has the same dimensions as a standard DVD or CD.
The name Blu-ray Disc is derived from the blue-violet laser used to read and write this type of disc. Because of its shorter wavelength (405 nm), substantially more data can be stored on a Blu-ray Disc than on the DVD format, which uses a red (650 nm) laser. A dual layer Blu-ray Disc can store 50 GB, almost six times the capacity of a dual layer DVD.
Blu-ray Disc was developed by the Blu-ray Disc Association, a group of companies representing consumer electronics, computer hardware, and motion picture production. The standard is covered by several patents belonging to different companies. As of March 2007, a joint licensing agreement for all the relevant patents had not yet been finalized.
As of February 19, 2008, more than 450 Blu-ray Disc titles have been released in the United States, and more than 250 in Japan.
During the high definition optical disc format war, Blu-ray Disc competed with the HD DVD format. On February 19, 2008, Toshiba — the main company supporting HD DVD — announced it would no longer develop, manufacture and market HD DVD players and recorders, leading almost all other HD DVD supporters to follow suit.
