DVD Writable and Rewritable
In addition to DVD-ROM, there are three writable DVD formats—DVD-R(A) for authoring, DVD-R(G) for general recording, and DVD+R—and three rewritable DVD formats, DVD-RW, DVD-RAM, and DVD+RW. All DVD writers and rewriters can read DVD-ROM discs, but each records to its own type of disc, none of which is fully compatible with any other or with existing standard DVD-ROM drives and players.
Incompatibility between the various standards has hindered the market acceptance of all of them, a problem that manufacturers have begun to address by introducing hybrid devices that read and write more than one format. For example, Pioneer produces a combination DVD-R and DVD-RW drive that also writes CD-R and CD-RW, and next-generation DVD-RAM drives will read and write DVD-RAM, DVD-RW, and CD-R/RW. As time passes, we expect this trend to continue.
The DVD Forum has introduced a DVD Multi logo that certifies compatibility with DVD-R, DVD-RW, and DVD-RAM. (Although not with DVD+RW—the DVD Forum and the DVD+RW Alliance don’t much like each other.) A DVD Multi drive or player can play all three formats, and a DVD Multi writer can write all three formats.
Here are the competing writable/rewritable DVD formats:
DVD-R (Recordable) was the first recordable DVD standard. DVD-R uses organic dye technology, and is similar conceptually to CD-R. DVD-R discs can be read by most DVD-ROM drives and DVD players. DVD-R 1.0 drives shipped in late 1997, cost $17,000 and stored 3.95 ...