Triple-layer discs (100 GB) and quadruple-layer discs (128 GB) are available for BD-XL re-writer drives. Conventional or 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.

The polycarbonate disc is 120 millimetres (4.7 in) in diameter and 1.2 millimetres (0.047 in) thick, the same size as DVDs and CDs. The name 'Blu-ray' refers to the blue laser (which is 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, PlayStation 5, Xbox One, and Xbox Series X. It is designed to supersede the DVD format, and capable of storing several hours of high-definition video (HDTV 720p and 1080p).

It was invented and developed in 2005 and released on Jworldwide. The Blu-ray Disc ( BD), often known simply as Blu-ray, is a digital optical disc data storage format.

High-Definition Versatile Multilayer Disc (HD VMD).

HD DVD: HD DVD-R, HD DVD-RW, HD DVD-RAM.

Blu-ray Disc ( BD): BD-R & BD-RE, Blu-ray 3D, Mini Blu-ray Disc.

DVD: DVD-R, DVD+R, DVD-R DL, DVD+R DL, DVD-R DS, DVD+R DS, DVD-RW, DVD+RW, DVD-RAM, DVD-D, DVD-A, DVD-Video, HVD, EcoDisc, MiniDVD.

Compact disc ( CD): CD-DA, CD-ROM, CD-R, CD-RW, 5.1 Music Disc, Super Audio CD ( SACD), Photo CD, CD Video ( CDV), Video CD ( VCD), Super Video CD ( SVCD), CD+G, CD-Text, CD-ROM XA, CD-i, MIL-CD, Mini CD.

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