Blu-ray, HD DVD aim to become standard-bearers of high-definition TV technology

WHAT ARE BLU-RAY AND HD DVD?: They pine to succeed the common DVD. The new technologies are meant for high-definition flat-screen televisions.

Blu-ray and HD DVD are incompatible formats, which means a Blu-ray player can't play HD DVD movies and vice versa.

The equipment to play the discs is expensive, and each side is fighting for acceptance from a market still saturated with regular DVDs.

The battle is compared to the videocassette recorder format war that led to VHS dominating Betamax.

SO WHAT'S THE BIG DEAL?: A standard DVD holds up to 8.5 gigabytes of data or movies. HD DVD stores up to 30 GB and Blu-ray 50 GB. The Blu-ray standard is spearheaded by Sony, HD DVD by Toshiba.

It all gets really technical, but as the Engadget tech blog puts it: "Blu-ray discs are more expensive, but hold more data [than HD DVD] -- there, that's all."

SO WHAT DOES THIS HAVE TO DO WITH VIDEO GAMES?: Sony's PlayStation 3 will use Blu-ray discs. Blu-ray is part of the reason for the console's higher cost.

Even if the PlayStation is used solely as a Blu-ray player, tech analyst David Riley notes, its $500 to $600 price is a bargain compared with the $1,000 average of most Blu-ray players.

Xbox 360, meanwhile, uses standard DVDs but is expected to release an external HD DVD movie player before Christmas. Both consoles have graphics built for playing on high-def TVs.