Is Blu-ray the same thing as HD-DVD?
No, HD-DVD, also known as AOD (Advanced Optical Disc) is the name of a competing next-generation optical disc format developed by Toshiba and NEC. The format is similar to Blu-ray and also utilizes blue-laser technology to achieve a higher storage capacity. The rewritable versions of the discs will be able to hold 20GB on a single-layer disc and 32GB on a dual-layer disc, while the read-only discs only will be able to hold 15GB on a single-layer disc and 30GB on a dual-layer disc. The read-only version of the format has been approved by the DVD Forum as the successor to the current DVD technology. 3.2 What’s the difference between Blu-ray and HD-DVD? UPDATED Parameters BD BD HD-DVD HD-DVD Recording capacity 25GB 50GB 20GB 32GB Number of layers single-layer dual-layer single-layer dual-layer Laser wavelength 405nm 405nm 405nm 405nm Numerical aperture (NA) 0.85 0.85 0.65 0.65 Protection layer 0.1mm 0.1mm 0.6mm 0.
