High Density Digital Versatile Discs
The first volley in the war for next generation optical storage
HD DVD stands for High Density Digital Versatile Disc. This was to be the unified standard for high-resolution DVD backed by NEC, Toshiba and Sanyo and recently Microsoft. But now it has ended up being a slightly downgraded competitor to Blu-Ray. Like Blu-Ray, HD DVD is a blue laser optical storage format using the 405nm wavelength blue laser. The blue laser has a narrower focus than the red laser used by conventional DVD and CD, meaning it will pick up data that is packed more densely than a standard DVD. The net effect is a storage medium with amazing mass storage properties.
The basic single-layer HD DVD can hold 15GB of data, while a dual layer is capable of 30GB of data. Toshiba announced development of a triple-layer HD DVD disc that will be capable of even more, up to 45GB of storage. A dual layer HD DVD (30GB) will be capable of over 4 hours of high-definition video with an accompanying multi-channel audio track. This is more than enough for use with high-definition movies and has already been adopted by major movie studios.