DVD Demystified

What Is DVD?
DVD is just DVD. In the early days of DVD’s development, the letters
stood for digital video disc. Later, like a stepsister trying to squish her ugly
foot into a glass slipper, a few companies tried to retrofit the acronym to
“digital versatile disc” in a harebrained attempt to express the versatility of
DVD. But just as everyone knows what a VCR and a VHS tape are without
worrying what the letters stand for, 2 DVD stands on it own.
But what is DVD? Put simply, DVD is the next generation of CD technology.
Improvements in optical technology have made the tightly packed
microscopic pits that store data on an optical disc even more microscopic
and even more tightly packed. A DVD is the same size as the familiar CD—
12 centimeters wide (about 4.7 inches)—but it stores up to 25 times more
and is more than nine times faster.
And yet, DVD is much more than CD on steroids. Its increased storage
capacity and speed allow it to accommodate high-quality digital video in
MPEG-2 format. The result is a small, shiny disc that holds better-than-TV
video and better-than-CD audio. A basic DVD can contain a movie over two
hours long. A double-sided, dual-layer DVD can hold about eight hours of
near-cinema-quality video or more than 30 hours of VHS-quality video. If
only still pictures are used, DVD becomes an audio book that can play continuously
for weeks.
DVD has many tricks to woo both the weary couch potato and the multimedia
junkie alike, such as a widescreen picture, multichannel surround
sound, multilingual audio tracks, selectable subtitles, multiple camera
angles, karaoke features, seamless branching for multiple storylines, navigation
menus, instant fast forward/rewind, and more.
Just as audio CD has its computer counterpart in CD-ROM, DVD has
DVD-ROM, which goes far beyond CD-ROM. DVD-ROM holds from 4.4 to 16
gigabytes of data—25 times as much as a 650-megabyte CD-ROM—and
sends it to the computer faster than a comparable CD-ROM drive.
DVD is inexpensive. The first few generations of DVD-ROM drives were
more expensive than CD-ROM drives, but as the technology has improved
and production quantities have increased, the price gap between them has
continued to narrow. Once the price gap is insignificant, manufacturers will
stop making CD-ROM drives. During the first few years, DVD-Video players
were as expensive as high-end VCRs, but mass production of DVD-ROM
drives and plummeting costs of audio/video decoder chips are driving the
price of consumer DVD players down to the same level as VCRs and CD
2 Some people claim VHS stands for video home system, whereas others insist it stands for video
helical scan or vertical helical scan. Just as with DVD, it is better to ignore the fuzzy etymology.
3