ABCs of DVD Drive Abbreviations
The number of different formats available in DVD drives can be
confusing to anyone in the market for one. The list is much longer, but to
address a few of the common formats, we have DVD-ROM, DVD-R, DVD-RW, DVD+R,
DVD+RW, DVD-RAM ,DVD+R DL and DVD±RW. Wow! This list of common formats is
long enough, no wonder it's confusing!
What's with all the Formats?!
The reason for various recordable DVD formats is that no one group
owns the technology and different groups have chosen to support one
technology over another. There is no industrial standard for manufacturers
to reference, so for the time being consumers will have a few choices.
The first thing to address is DVD itself, which stands for Digital Versatile
Disc. Some may argue that the V stands for Video, but with the capability to
store video, audio, and data files, Versatile is definitely the keyword.
Start with the Basics
A DVD-ROM drive is the only one we will address that does not
record. ROM stands for Read Only Memory, and refers to the typical drive
that can merely read DVDs, as well as CDs (all DVD drives can read CDs). The
Lite-On LTD-163-DO-R has attributes representative of your typical DVD-ROM
drive, and features a maximum DVD read speed of 16x and a maximum CD read
speed of 48x. Before getting into the different recordable formats, let's
address the basics of what the R and RW stand for, regardless of whether
there is a + or – in the middle. R stands for Recordable, which indicates
that the disk may be recorded to only once. RW stands for ReWritable, which
indicates that the disc may be recorded to more than once, and are generally
rated for 1000 rewrites under good conditions. The DVD-R/-RW format was
developed by Pioneer, and was the first format compatible with stand alone
DVD players. The group that promotes the technology calls itself the DVD
Forum, which is "an international association of hardware manufacturers,
software firms, content providers, and other users" with notable members
such as Hitachi, Samsung, and Toshiba. The DVD-R/-RW format is based on
CD-RW technology and uses a similar approach to burning discs.
The DVD+R/+RW format is a newer format, also based on CD-RW
technology, and compatible with a large percentage of stand alone DVD
players. The +R/+RW technology is not supported by the DVD Forum, and its
main backing comes from a group called the DVD+RW Alliance. The Alliance "is
a voluntary group of industry-leading personal computing manufacturers,
optical storage and electronics manufacturers" with members such as Dell,
Hewlett Packard, Sony, and Phillips Electronics.
The DVD-RAM format is based on PD-RW (Phase-Differential) drives, and
actually uses a cartridge to hold the media (just like its PD-RW
predecessor). Some DVD-RAM cartridges are double sided, making them ideal
for companies to use as system backup, hence DVD-RAM is usually found only
in commercial applications, and most end-users won't ever need to use or see
this type of drive. The DVD-RAM standard is also supported by the DVD Forum
just like the DVD-R/RW format. However, because of its use of a cartridge
(limiting it's compatibility), and the scarcity and price of the media used,
DVD-RAM is a distant third when compared to the DVD+R/+RW and DVD-R/–RW
The +R/+RW and –R/-RW formats are similar, and the main difference
DVD+R technology has is the ability to record to multiple layers (with its
new DVD+R DL format), where DVD-R can only record to one layer (not all +R
drives are capable of dual layer burning, but no -R drives are). The Plextor
PX-504U is an example of an external DVD+R/+RW drive capable of recording
single layer discs in the +R/+RW format, but also able to read discs
recorded by a DVD-R drive.
What is DVD±RW?
DVD±RW is not actually a separate format, but the designation given
to drives capable of both –R/–RW and +R/+RW operation. This type of drive is
typically called a "Dual Drive" (not to be confused with a "Double Layer"
drive) since it can write to both the +R/+RW and –R/–RW formats. The Samsung
TS-H552 is a DVD±RW drive capable of reading and writing every format
discussed so far, and then some. It takes advantage of DVD+R DL (Double
Layer) technology available with the +R format, allowing the appropriate
media to store virtually double the 4.37 GB capacity of a typical single
The other main thing to consider with DVD burners is selecting the
correct media. Media for DVD-R, DVD-RW, DVD+R and DVD+RW media may all look
the same, but they are slightly different in order to match the specific
recording formats. The price of media for either format is generally the
same, with RW media costing a good deal more than R media of either format.
Double Layer media is even more expensive, and is the only way for an owner
of DVD+R DL drive to take advantage of the tremendous capacity increase. As
the amount of Double Layer drives increase in the market, the price of the
DVD+R DL media is expected to fall with increased production of the media.
DVD Burners (as these drive are often referred to) can be picky about the
media supported, so be sure to choose your media wisely.
DVD in a Nutshell
DVD-ROM : Reads DVD discs
DVD+R : Writes to DVD+R media (will also typically write to CD-R and CD-RW
DVD+RW : Writes to DVD+RW media (will also typically write to DVD+R, CD-R
and CD-RW media)
DVD+R DL : Writes to DVD+R DL (Double Layer) media (will also typically
write to DVD+R, DVD+RW, CD-R and CD-RW media; many Double Layer drives are
ALSO dual drives – that is, able to write to BOTH +R/RW and –R/RW media)
DVD-RAM : Writes to DVD-RAM cartridges (not in wide use on consumer market –
mainly a business format; can also read PD-RW discs. Will not usually be
able to write to any other format including CD-R or CD-RW)
DVD-R : Writes to DVD-R media (will also typically write to CD-R and CD-RW
media) DVD-RW : Writes to DVD-RW media (will also typically write to DVD-R,
CD-R and CD-RW media)
DVD±RW : Writes to DVD-RW and DVD+RW media (will also typically write to
DVD-R, DVD+R, CD-R and CD-RW media; typically called "Dual Drives" since it
can burn to two different DVD formats)
This article took a look at the more common formats of DVD drives in
order to shed some light on all the choices available. The differences
between them all may be subtle, but the compatibility issues can be quite
frustrating. The simple answer to anyone considering a drive is to forget
about + and – by themselves, and shoot for universal compatibility with a
good DVD±RW with DVD+R DL support.