The benefit of using a blue laser is that blue light has a shorter wavelength so that it can be focused on a smaller target area than a red light laser. This allows data to be packed in more densely allowing more space for data in same sized physical space.

Blu ray is called Blu ray because it uses a blue light laser to write data onto disc.

Blu ray is expected to replace VCRs and DVD players and recorders over coming years because Blu ray offers so much more capacity. Although it will take time for Blu ray technology to be come wide spread because cost of DVD drives and media is so much cheaper than Blu ray at this time.

There are two kinds of of HD DVD discs for content, 15GB single layer disc and dual-layer disc with double capacity, a full 30GB. Using latest compression technologies, 30Bg disc can store up to 7 hours of images. Today' DVD has a capacity of 4.7GB and store only 2 hours of standard definition content.

HD DVD discs have a data transfer rate of 36.55Mbps which allows 24Mbps data stream of digital television broadcasts to be seamlessly recorded.

Using HD DVD in every day world will have numerous advantage over other optical media technologies. The resilient HD DVD disc has a protective layer which removes need for a protective cartridge, allowing development of slim computer drives. The added bulk of a disc cartridge would have also caused any laptops using a cartridge based optical media disc to increase substantially in size to allow for extra room drive would need.