There are actually three types of DVD players in the marketplace: the ubiquitous standard DVD player; the High-Definition (HD) DVD player that is perhaps less well-known; and the Blu-ray player. When references are made to “DVD versus Blu-ray” the comparison is between the HD DVD player and Blu-ray player. Both are high-capacity players that use a proprietary HD format, which pitted the technologies against each other for market dominance. The format war essentially ended on 22 February 2008 when Toshiba announced it would cease manufacturing the HD DVD player.

High-definition video requires plenty of disc storage. The secret to the Blu-ray player and HD DVD is that they both use blue lasers rather than the red lasers used in standard DVD/CD players. The pinpoint focus of a laser is the tool that produces the pits and lands on the surface of a disc, later read as digital bits. A smaller or more refined beam can burn tinier pits (more bits) on the surface of the disc, resulting in greater data capacity. Blue light has a shorter wavelength than red light, producing a more tightly focused beam. The blue laser is therefore capable of burning more data than a red laser into the same size space.

A standard DVD player can store about 8.5 gigabytes (GB) of information on a dual/double layer (DL) DVD disc. The HD DVD player places 30 GB on a DL HD disc; while the Blu-ray player stores 50 GB on a DL Blu-ray disc. Optical format strategies for even greater capacities are on the horizon. For reference, a standard length movie in high-definition consumes about 15 GB.

Blu-ray DVD movie releases and Blu-ray formatted discs will not play on HD DVD players, and visa-versa. Consumers can buy a "combo" player that supports both Blu-ray and HD DVD, but this can be more expensive than buying an HD DVD and Blu-ray player both. However, prices for combo players might now fall.

The Blu-ray player is backwards compatible with standard DVD/CDs (as is the HD DVD), which is good news for consumers who have diligently built music and movie libraries with red laser technology. As for those new burns to Blu-ray discs, you’ll pay more the media than the older, standard discs.

An HD DVD player is considerably less expensive than a Blu-ray player, but costs should drop across the board. Microsoft™ who backed HD DVD, makes an add-on HD DVD player for the Xbox™ 360, while Sony™ makes an add-on Blu-ray player for PlayStation™ 3. At the time of this writing Microsoft is rumored to be planning a Blu-ray add-on for the XBox, expected as early as May 2008. Stand-alone players and combo players are also available from leading electronics manufacturers.