DVD+RW is an optical storage rewritable disc format created by the DVD+RW Alliance as a market competitor of the DVD-RW (dash) format. It holds a high capacity of audio and video that can be read, written, erased and re-written dependably up to 1,000 times per disc. The format can accommodate one or two layer discs. DVD+RW was publicly introduced in 2001 at a 4.7B storage capacity.
DVD+RW debuted before its write-once counterpart, DVD+R - a trend that was contrary to the dash format's line of optical storage. The DVD+RW Alliance includes these manufacturers and are also subject to change: Philips, Sony, Hewlett-Packard, Mitsubishi, Yamaha and Ricoh.
A winner of the DVD format war between the "dash" and "plus" media remains to be determined as the development of more hybrid players and drives provides more equal playing ground for user compatibility.
The layers of the disc are similar to those of a DVD-RW. The recording layer is a metal alloy that changes states from crystalline to amorphous to alter the reflectivity. The deviations in reflectivity are interpreted as data that is either read, written, erased or rewritten by the drive's optical devices.
The DVD+RW has insulated layers to draw excess heat away from the recording layer, a metallic reflective layer and two polycarbonate substrates. Microscopic indentations (called pits and lands) contain binary data that imprints the recording layer via the laser.
What sets DVD+RW apart from its dash format competitor is its lossless linking system. The process of encoding recorded data at variable bit rate traditionally utilizes a significant amount of space, causing considerable stopping and starting of the disc which in turn creates link loss.
Link loss is responsible for incompatibility with players and drives; however, DVD+RW's system can encode variable bit rate without the link loss. This enables the user to work with more of the disc's data and have more efficient random access to tracks.
DVD+RW disks can be read by a majority of DVD recorders, DVD-ROM drives and consumer electronics, but the lower reflectivity that's characteristic in this media format may cause some occasional incompatibility issues.
Be sure to check out our pages on these other DVD formats:
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