why blue ray dvd is better than hd dvd?

I don't really know what the mini-disc has to do with Blu-Ray and HD DVD, but anyway Blu-Ray's are theoretically better because they can hold more data, 25GB on a layer as opposed to 15GB for HD DVD. But Blu-Ray is also more expensive to manufacture, so that will be the real test, if they can get the manufacturing costs down.

I think Blue Ray will become a great PC storage medium because of it's large GB capacity.
HD will become the standard of Hi-Def movies, both these formats will only survive if the prices drop.

Look at all these long-winded anwers! Geez!

The only differences:

Blu-ray: Holds 20GB more (approx. 80GB) this means that, in addition to the main movie, the special features can also be in Hi-Def. Is backed by 4 of the 5 major movie studios, which may lead to more movies for this format. Expensive player (USD $999). Backed by Sony - which has a history of failures in special formats.

HD-DVD: Cheaper player (USD $199-599). Backed by Microsoft. Hi-Def only on feature film, not on extras.

Right now, neither side looks like the clear winner.

fact of the matter is the PlayStation 2 is in over 40% of the homes in America. The PlayStation 3 is anticipated to achieve higher numbers -- and the PS3 had a blue ray player. Come Christmas 2006 -- 2 million PS3's will be introduced worldwide and over 100 million slotted by Christmas 2007. Even with the introduction of an "HD add-on player" for the XBOX 360, the number of PS3's will turn blue ray into the dominate technology.

IMO, blue ray will fail. Look at mini-disc. HD-DVD will suceed and will be the standard.