Blu-ray Disc (also known as BD or Blu-Ray) is an optical discstorage medium designed to supersede the standard DVD format.
Its main uses are for storing high-definition video, PlayStation 3video games, and other data, with up to 25 GB per single layered, and 50 GB per dual layered disc prototypes. Although these numbers represent the standard storage for Blu-Ray drives, the specification is open-ended, with the upper theoretical storage limit left unclear. 200 GB discs are available, and 100 GB discs are readable without extra equipment or modified firmware. The disc has the same physical dimensions as standard DVDs and CDs.
The name Blu-ray Disc derives from the blue-violet laser used to read the disc. While a standard DVD uses a 650 nanometer red laser, Blu-ray uses a shorter wavelength, a 400 nm blue-violet laser, and allows for almost ten times more data storage than a DVD.
During the format war over high-definition optical discs, Blu-ray competed with the HD DVD format. Toshiba, the main company supporting HD DVD, ceded in February 2008, and the format warended; in July 2009, Toshiba announced plans to put out its own Blu-ray Disc device by the end of 2009.
Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of June 2009, more than 1,500 Blu-ray disc titles are available in Australia, with 2,500 in Japan, 1,500 in the United Kingdom, and 2,500 in the United States andCanada