WHAT Is Blu-ray Disc...??

Blu-ray Disc (official abbreviation BD) is an optical disc storage medium designed to supersede the DVD format. The format defines as its standard physical media a 12 cm (same as DVDs and CDs), 25 GB per-layer optical disc, with dual layer discs (50 GB) the norm for feature-length video discs and additional layers possible later.

The name Blu-ray Disc refers to the blue laser used to read the disc, which allows for six times more storage than on a DVD. The term Blu was used instead of the correct Blue which is commonly used in English (and therefore not registrable as a trademark).
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 were available in Australia and the United Kingdom, with 2,500 in the United States and Canada. In Japan as of July 2010 more than 3,300 titles were released.
During the high definition optical disc format war, Blu-ray Disc competed with the HD DVD format. Toshiba, the main company that supported HD DVD, conceded in February 2008,[4] releasing their own Blu-ray Disc player in late 2009.
Blu-ray Disc recordable
Main article: Blu-ray Disc recordable
"Blu-ray Disc recordable" refers to two optical disc formats that can be recorded with an optical disc recorder. BD-Rs can be written to once, whereas BD-REs can be erased and re-recorded multiple times. The current practical maximum speed for Blu-ray Discs is about 12×. Higher speeds of rotation (10,000+ rpm) cause too much wobble for the discs to be read properly, as with the 20× and 52× maximum speeds, respectively, of standard DVDs and CDs.
Since September 2007, BD-RE is also available in the smaller 8 cm Mini Blu-ray Disc size.
On September 18, 2007, Pioneer and Mitsubishi codeveloped BD-R LTH ("Low to High" in groove recording), which features an organic dye recording layer that can be manufactured by modifying existing CD-R and DVD-R production equipment, significantly reducing manufacturing costs.[64] In February 2008, Taiyo Yuden, Mitsubishi, and Maxell released the first BD-R LTH Discs, and in March 2008, Sony's PlayStation 3 gained official support for BD-R LTH Discs with the 2.20 firmware update.[66] In May 2009 Verbatim/Mitsubishi announced the industry's first 6X BD-R LTH media, which allows recording a 25 GB disc in about 16 minutes.
Unlike the previous releases of 120 mm optical discs (i.e., CDs and standard DVDs), Blu-ray recorders hit the market almost simultaneously with Blu-ray's debut.



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