An optical disc storage medium designed to supersede the standard DVD format. The name 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 405 nm blue-violet laser, and allows for
almost ten times more data storage than a DVD
Its main uses are for storing high-definition video, PlayStation 3 video games, and other data. Basically it is like a DVD and game player that can also download television shows and movies.
Technically speaking, it has up to 25 GB per single layered, and 50 GB per dual layered disc. 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.
Historical perspective: During the format war over high-definition optical discs, Blu-ray competed with the HD DVD format. Toshiba, the main company supporting HD DVD, conceded in February 2008, and the format war ended; 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 and the United Kingdom, with 2,500 in Japan, the United States and Canada.