Blu-ray Disc

Blu-ray Disc (also known as Blu-ray or BD) is an optical disc storage medium designed by Sony to supersede the DVD format. Its main uses are high-definition video and data storage with 50GB per disc. The disc has the same physical dimensions as standard DVDs and CDs.

The name Blu-ray Disc is derived from the blue laser (violet-colored) used to read and write to this type of disc. In part because of the shorter wavelength (405 nanometres), substantially more data can be stored on a Blu-ray Disc than on a DVD, which uses a red (650 nm) laser. A dual-layer Blu-ray Disc can store 50 gigabytes, almost six times the capacity of a dual-layer DVD, or ten and a half times that of a single-layer DVD.

During the format war over high-definition optical discs, Blu-ray Disc competed with the HD DVD format. On February 19, 2008, Toshiba—the main company supporting HD DVD—announced that it would no longer develop, manufacture, or market HD DVD players and recorders, leading almost all other HD DVD companies to follow suit, effectively ending the format war.

Blu-ray Disc is developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of December 21, 2008, more than 890 Blu-ray disc titles are available in Australia, more than 720 Blu-ray Disc titles are available in Japan, more than 1,140 Blu-ray Disc titles are available in the United Kingdom, and more than 1,500 Blu-ray Disc titles are available in the United States.