Difference between Blu-ray and HD DVD

1. Blu-ray :
Blu-ray is a digital optical disk of large data storage that is developed by the Blu-ray Disc Association that is capable of storing many hours of video in high-definition. In blu-ray, the maximum bitrate of raw data, audio as well as video and video only is 53.95 Mbps, 48 Mbps and 40 Mbps respectively. It is thicker than DVD but similar to HD DVD.

2. HD DVD :
HD DVD stands for short for High Definition Digital Versatile Disc. It is developed by DVD Forum Toshiba. It is the successor to DVD, an optical disc for storing large data than DVD and playback of high-definition video. In HD DVD, the maximum bitrate of raw data, audio as well as video and video only is 36.55 Mbps, 30.24 Mbps and 29.4 Mbps respectively.

Difference between Blu-ray and HD DVD :

S.NO	Blu-ray	HD DVD
1.	Blu-ray has a single layer storage size of 25 GB.	While HD DVD has a single layer storage size of 15 GB.
2.	The Blu-ray laser wavelength is 405 nanometers.	While its laser wavelength is also 405 nanometers but lower than the DVD laser wavelength.
3.	The Blu-ray numerical aperture is 0.85.	While its numerical aperture is 0.65.
4.	In Blu-ray, hard coating of the disc is mandatory.	Whereas in HD DVD, hard coating of disc is optional.
5.	Blu-ray has a double layer storage size of 50 GB.	While HD DVD has a double layer storage size of 30 GB.
6.	Blu-ray is more expensive than HD DVD.	While it is cheaper than Blu-ray.
7.	The Blu-ray Disc Association developed Blu-ray.	Whereas it is developed by DVD Forum Toshiba.
8.	The Blu-ray data transfer speed is 4.5 MB/sec.	While its data transfer speed is around 4.5 MB/sec which is higher than DVD.