A disc that works in both DVD-Video players and DVD-ROM PCs. (The most common use of the term hybrid, but more accurately called an enhanced DVD) A DVD-ROM disc that runs on Windows and Mac OS computers. (More accurately called a cross-platform DVD.) A DVD-ROM or DVD-Video disc that also contains Web content for connecting to the Internet. (More accurately called a WebDVD or Web-connected DVD.) A disc that contains both DVD-Video and DVD-Audio content. (More accurately called a universal or AV DVD.) A disc with two layers, one that can be read in DVD players and one that can be read in CD players. (More accurately called a legacy or CD-compatible disc.). One side can be read by CD players, the other side by DVD players. The resulting disc is 0.6 mm thicker than a standard CD or DVD, which can cause problems in players with tight tolerances, such as portables. DVDPlus is colloquially known as a "fat" disc. Both layers are read from the same side, with the CD player being required to read through the semitransparent DVD layer, causing problems with some CD players.

By, Jim Taylor Author of DVD Demystified and the DVD FAQ The entire FAQ can be found at http://dvddemystified.com/dvdfaq.html