Blu-ray or
Blu-ray Disc (
BD,
BRD) is a
digital optical disc data storage format. It was designed to supersede the
DVD format, in that it is capable of storing
high-definition video resolution (
1080p). The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and
CDs. Conventional (pre-BD-XL) 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-layers (128 GB) are available for
BD-XL re-writer drives. The name "Blu-ray" refers to the
blue laser (specifically, 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 physical distribution of video games for the
PlayStation 3,
PlayStation 4, and
Xbox One. Besides the hardware specifications, Blu-ray is associated with a set of multimedia formats.
