Specifications

Note: the DVD capacity is measured in the so called decimal gigabytes (one gigabyte is equal to 1000
megabytes). The real size of the DVDs is smaller when measured in the so called computer gigabytes or
gibibytes (one gigabyte is equal to 1024 megabytes).
The
disc medium can be:
DVD-ROM (read only, industrially manufactured)
A factory-made DVD that is manufactured by a press. The DVD specification Version 1.0 was announced in 1995 and finalized in
September 1996. "DVD" was originally an acronym for "digital video disc"; some members of the DVD Forum believe that it should
stand for "digital versatile disc", to indicate its potential for non-video applications. Toshiba adheres to the interpretation of "digital
versatile disc". The DVD Forum never reached a consensus on the matter, however, and so today the official name of the format is
simply "DVD"; the letters do not "officially" stand for anything.
DVD-R (R = Recordable once)
A DVD-Recordable or DVD-R is an optical disc with a larger storage capacity than a CD-R, typically 4.7 GB instead of 700 Mb, although
the capacity of the original standard was 3.95 Gb. The DVD-R format was developed by Pioneer in autumn of 1997. It is supported by
most DVD players, and is approved by the DVD Forum. A DVD-R can be written to only once.
DVD-RW (RW = ReWritable)
A DVD-RW is a rewritable optical disc with equal storage capacity to a DVD-R, typically 4.7 GB. The format was developed by Pioneer
in November 1999 and has been approved by the DVD Forum. Unlike DVD-RAM, it is playable in about 75% of conventional DVD
players. The primary advantage of DVD-RW over DVD-R is the ability to erase and rewrite to a DVD-RW disc. According to Pioneer,
DVD-RW discs may be written to about 1,000 times before needing replacement, making them comparable with the CD-RW standard.
DVD-RW discs are commonly used for volatile data, such as backups or collections of files. They are also increasingly used for home
DVD video recorders.
DVD-R DL (double layer)
DVD-R DL (Dual Layer) (Also Known as DVD-R9) is a derivative of the DVD-R format standard. DVD-R DL discs employ two
recordable dye layers, each capable of storing nearly the 4.7 GB of a single-layer disc, almost doubling the total disc capacity to 8.54
GB. Discs can be read in many DVD devices (older units are less compatible) and can only be written using DVD±RW DL burners.
DVD+R (R = Recordable once)
A DVD+R is a writable optical disc with 4.7 GB of storage capacity. The format was developed by a coalition of corporations, known as
the DVD+RW Alliance, in mid 2002. Since the DVD+R format is a competing format to the DVD-R format, which is developed by the
DVD Forum, it has not been approved by the DVD Forum, which claims that the DVD+R format is not an official DVD format. The
DVD+R format is divergent from the DVD-R format. Hybrid drives that can handle both, often labeled "DVD±RW", are very popular
since there is not yet a single standard for recordable DVDs. There are a number of significant technical differences between the dash
and plus formats, and although most consumers would not notice the difference, the plus format is considered by some to be better
engineered.
DVD+RW (RW = ReWritable)
A DVD+RW is a rewritable optical disc with equal storage capacity to a DVD+R, typically 4.7 GB (interpreted as 4.7 · 109, actually
2295104 sectors of 2048 bytes each). The format was developed by a coalition of corporations, known as the DVD+RW Alliance, in
late 1997, although the standard was abandoned until 2001, when it was heavily revised and the capacity increased from 2.8 GB to
4.7 GB. Credit for developing the standard is often attributed unilaterally to Philips, one of the members of the DVD+RW Alliance.
Although DVD+RW has not yet been approved by the DVD Forum, the format is too popular for manufacturers to ignore, and as such,
DVD+RW discs are playable in 3/4 of today's DVD players. Unlike the DVD-RW format, DVD+RW was made a standard earlier than
DVD+R.
DVD+R DL (double layer)
DVD+R DL (Double Layer), also known as DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance. Its use
was first demonstrated in October 2003. DVD+R DL discs employ two recordable dye layers, each capable of storing nearly the 4.7 GB
of a single-layer disc, almost doubling the total disc capacity to 8.55 GB. Discs can be read in many DVD devices (older units are less
compatible) and can only be created using DVD+RW DL and Super Multi drives. The latest DL drives write double layer discs slower
AVS4YOU Programs Help - Appendix
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