Blu-ray Disc

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 laser (violet coloured) 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 double-dual layer DVD (or more than 10 times if single-layer).
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 companies to follow suit, effectively ending the format war.
Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing consumer electronics, computer hardware, and motion picture production. As of August 27, 2008 more than 780 Blu-ray Disc titles have been released in the United States and more than 480 Blu-ray Disc titles have been released in Japan.By the end of 2008, there is expected to be a total of 1192 Blu-ray Disc titles released.

Competition from HD DVD
The DVD Forum (which was chaired by Toshiba) was deeply split over whether to develop the more expensive blue laser technology or not. In March 2002, the forum voted to approve a proposal endorsed by Warner Bros. and other motion picture studios that involved compressing HD content onto dual-layer DVD-9 discs.In spite of this decision, however, the DVD Forum's Steering Committee announced in April that it was pursuing its own blue-laser high-definition solution. In August, Toshiba and NEC announced their competing standard Advanced Optical Disc.It was finally adopted by the DVD Forum and renamed HD DVD the next yearafter being voted down twice by Blu-ray Disc Association members, prompting the U.S. Department of Justice to make preliminary investigations into the situation.HD DVD had a head start in the high definition video market and Blu-ray Disc sales were slow at first. The first Blu-ray Disc player was perceived as expensive and buggy, and there were few titles available.This changed when PlayStation 3 launched, since every PS3 unit also functioned as a Blu-ray Disc player. At CES 2007 Warner proposed Total Hi Def which was a hybrid disc containing Blu-ray on one side and HD DVD on the other but it was never released. By January 2007, Blu-ray discs had outsold HD DVDs,and during the first three quarters of 2007, BD outsold HD DVDs by about two to one. Finally, by February 2008, Toshiba announced it was pulling its support for the HD DVD format, leaving Blu-ray as the victor in the video wars.
Some analysts believe that Sony's PlayStation 3 video game console played an important role in the format war, believing it acted as a catalyst for Blu-ray Disc, as the PlayStation 3 used a Blu-ray Disc drive as its primary information storage medium.They also credited Sony's more thorough and influential marketing campaign.More recently Twentieth Century Fox have cited Blu-ray Disc's adoption of the BD+ anti-copying system as the reason they supported Blu-ray Disc over HD DVD.