Blackwell Reference Online

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CD‐ROM and DVD disks are used for computer storage. Both technologies are in current use, but DVDs are becoming more common. The newer DVD‐ROM drives are designed to also read CD‐ROM disks and most will also record to CD‐R and CD‐RW disks. These technologies are ideal for data sets that are relatively static or for which many copies of the same data are required. They are therefore important to information systems in organizations as well as for consumer products. In a CD‐ROM (compact disk read‐only memory), information is permanently stored digitally and read by a CD‐ROM drive system using low‐intensity lasers. Each aluminum and plastic disk, measuring 120 mm in diameter and 1.2 mm thick, holds 700 megabytes (MB) of data. The technology began with audio CDs in 1982 (replacing vinyl long‐playing records). CD‐ROM was introduced in 1985. The standards (called the “Yellow Book” in the industry) for CD‐ROM are maintained by Koninklijke Philips Electronics NV ( www.licensing.philips.com/information/cd/video/ ). Other versions of the CD include: CD‐R (compact disk recordable) and CD‐RW (compact disk rewritable), which can be written to one time and multiple times, respectively, and various interactive CDs (CD‐I, CDTV, and other formats), which can store video, audio, and data. Photo CD is a format that holds digitized photographs and sound. Although DVD (digital versatile disk or digital ... log in or subscribe to read full text