DVD

Latest info says “DVD” no longer stands for anything! It used to mean “digital versatile disc” – and before that it meant “digital video disc.” A new type of 12-centimeter (4.72″) compact disc (same size as audio CDs and CD-ROMs) that holds 10 times the information. Capable of holding full-length movies and a video game based on the movie, or a movie and its soundtrack, or two versions of the same movie – all in sophisticated discrete digital audio surround sound. The DVD standard specifies a laminated single-sided, single-layer disc holding 4.7 gigabytes, and 133 minutes of MPEG-2 compressed video and audio. It is backwards compatible, and expandable to two-layers holding 8.5 gigabytes. Ultimately two discs could be bounded together yielding two-sides, each with two-layers, for a total of 17 gigabytes. There are three versions: DVD-Video (movies), DVD-Audio (music-only) and DVD-ROM (games and computer use). The DVD-Audio standard is still being defined. Meanwhile a fourth member has joined the family: DVD-RAM defines specs for a rewritable system, opening the door for recording.