A write-once, recordable format. DVD-R drives can write DVD-R discs, which can be written to only once, as opposed to a DVD-RW drive, which can write and rewrite to RW media multiple times. The Authoring Use Drive (635nm Laser) was introduced in 1998 by Pioneer, and the General Use Format (650nm Laser) was authorized in 2000. DVD-R offers a write-once, read-many storage format akin to CD-R and is used to master DVD-Video and DVD-ROM discs.
DVD ReWritable. A rewritable DVD format that is similar to DVD+RW, but its capability to work as a random access device is not as good as that of the +RW. DVD-RW has a read-write capacity of 4.7 GB.
Short for DVD+Recordable, a recordable DVD format similar to a CD-R. A DVD+R can only record data once and then the data becomes permanent on the disc. The disc can not be recorded onto a second time. DVD+R and DVD+RW formats are supported by Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha and others.
The DVD Plus RW Alliance is a group of companies that includes Philips and Sony. They propose standards for recordable and rewritable DVDs.
DVD+R Dual Layer /Double Layer Media:
Double Layer DVD+R media has an amazing 8.5GB of storage capacity. This incredible capacity is enough for up to 4 hours of DVD quality video, 16 hours of VHS quality video or over 120 hours of MP3 audio. Compatible with all current DVD video players and DVD-ROM drives as well as new DVD+R DL drives, the disc is ideal for virtually any business or household application.
Dual-layer DVD-R media offers genuine advantage over the current single layer 4.7GB DVD. The new dual-layer recordable DVD-R disc allows users to read, write or view almost twice the amount of data that is currently possible with the single layer. The advanced technology means that material can be read or recorded on one layer without affecting the other. There's no need to flip sides or change discs.
DVD Random Access Memory is a rewritable DVD disc endorsed by Panasonic, Hitachi and Toshiba. It is a cartridge-based, and more recently, bare disc technology for data recording and playback. DVD-RAM bare discs are fragile and do not guarantee data integrity. The first DVD-RAM drives had a capacity of 2.6GB (single-sided) or 5.2GB (double-sided). DVD-RAM Version 2 discs have double-sided 9.4GB discs. DVD-RAM drives typically read DVD-Video, DVD-ROM and CD media. The current installed base of DVD-ROM drives and DVD-Video players cannot read DVD-RAM media.