Greggles
11-04-2006, 3:39 PM
Both Blu-Ray and HD-DVD use a blue (rather than red on standard DVD) laser. This allows a far more pricise focusing of the beam, which in turn leads to more "bumps per inch" on the disk. Therefore HD-DVD players can play DVDs but not visaversa (I'm unsure about the backward compatibility of Blu-Ray)