Blu-ray Disc

Blu-ray Disc (also known as Blu-ray or BD), is an optical disc storage medium designed to replace the standard DVD format. Blu-ray Disk, the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson).

The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. The disc has the same physical dimensions as standard DVDs and CDs

Although the Blu-ray Disc specification has been finalized, engineers continue to work on advancing the technology. Recently, Pioneer Corporation unveiled a 400 GB Blu-ray Disc that will be compatible with current players after a firmware update. Its planned launch is in the 2009–10 time frames. Ongoing development is under way to create a 1 TB (1 TB = 1000 GB) Blu-ray Disc

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 405 nm blue-violet laser, and allows for almost six times more data storage than a DVD. Though not compulsory, the Blu-ray Disc Association recommends that Blu-ray Disc drives be capable of reading standard DVDs and CDs, for backward compatibility.