Digital versatile disc

Description

A type of Optical disk capable of storing up to 4.7 gigabytes of digital information. The digital videodisc, or DVD, was originally developed in 1995 by Philips Electronics and Sony Corporation. More recently, its name has been changed to digital versatile disc because it can reproduce not only high definition video images but other types of digital data as well. The DVD is composed of a flat, circular, polycarbonate substrate (12 cm diameter, 1.2 mm thick) coated with a reflective aluminum layer and a thin acrylic lacquer. The acrylic coating protects the metal from abrasion and corrosion. While the DVD's are physically the same dimensions as compact discs (CD), they are not interchangeable because the information is recorded differently. The DVD player uses a high-power red laser that has a finer focus point than that of the CD player. This laser allows smaller pits and narrower separation tracks thus providing the DVD's greater storage capacity.

Synonyms and Related Terms

DVD; digital versatile disk; digital videodisc; digital video disc; optical disk

Resources and Citations

• Encyclopedia Britannica, http://www.britannica.com Comment: "Compact Disc." Accessed 11 Sep, 2003 .