Blu-ray Disc
Overview
Blu-ray Disc (BD) is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 millimeters in diameter and 1.2 millimeters thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual-layer discs (50 GB) being the industry standard for feature-length video discs. Triple-layer discs (100 GB) and quadruple-layer discs (128 GB) are available for BD-XL re-writer drives.
History
The name "Blu-ray" refers to the blue laser (actually a violet laser) used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs. The main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, and Xbox One. The plastic disc is 120 millimeters in diameter and 1.2 millimeters thick, the same size as DVDs and CDs.
Specifications
Blu-ray Discs contain 25 GB per layer, with dual-layer discs (50 GB) being the industry standard for feature-length video discs. Triple-layer discs (100 GB) and quadruple-layer discs (128 GB) are available for BD-XL re-writer drives. The length of a full movie varies between 90 and 180 minutes, depending on the level of compression used. The audio and video quality of Blu-ray Discs is superior to that of DVDs, with support for up to 7.1 channel surround sound and video resolutions up to 1080p (progressive scan).
Applications
The main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, and Xbox One. The BD format was developed by the Blu-ray Disc Association, a consortium of several technology and media companies.