The Blu-ray Disc is an optical disc type primarily used for videos, created as a higher-capacity successor to the DVD. For a time it was in a format war with HD-DVD, ultimately winning out, but this victory came in a time when physical media were in decline in favor of streaming and downloads through networks as the preferred means of content distribution. This has slowed the adoption of Blu-ray compared to earlier media, but the format is widely supported nevertheless. Netflix has an option to receive Blu-ray Discs instead of DVDs when available, as part of the disc-in-the-mail subscriptions (which continue to have a wide range of material not presently available in streaming subscriptions).
Blu-ray Discs can be single-layer (25 GB capacity) or double-layer (50 GB). As with other optical disc types, they can be used for data, games, or audio, but the format is primarily marketed as a medium for video such as movies and TV shows. When used as a computer data storage medium, it may have a UDF filesystem.
The archival-quality M-Disc is available in BluRay form as well as DVD.
There is a Blu-ray 3D format as well for videos to be played in 3D (using special glasses) on supporting devices.
Standards and specs
- White Paper on Blu-ray Disc Format: General
- File System Specification
- BD-RE physical format (rewritable)
- BD-RE audo-visual application format 1
- BD-RE audo-visual application format 2
- BD-RE audo-visual application format 3
- BD-R physical format (recordable)
- BD-ROM physical format
- BD-ROM audio-visual format
- AVCREC rewritable format audio-visual spec