an optical disk, 4 3/4 inches (120 mm ) in diameter, on which program data, music, etc is digitally encoded for a laser beam to scan, decode, and transmit to a playback system, computer monitor, or television set
Compact Disc An impact resistant, transparent, polycarbonate plastic disc with a highly reflective vaporized aluminum surface using a digitally quided laser beam
A music disc holding stereo audio signals, coded with 44,100 samples/sec x 16 bits x 2 channels yielding a bit rate of 1 4Mbits/sec, a higher bit rate than used by Dolby Digital coding, but the same as the DTS bit rate
An optical disc on which data is encoded OCLC CatCD for Windows stores the Authority File and subsets of records from WorldCat on compact discs The subsets of records are for subject categories, for example, law or medicine
com·pact disc compact discs in AM, also use compact disk Compact discs are small shiny discs that contain music or computer information. The abbreviation CD is also used. CD a small circular piece of hard plastic on which high-quality recorded sound or large quantities of information can be stored. Molded plastic disc containing digital data that is scanned by a laser beam for the reproduction of recorded sound or other information. Since its commercial introduction in 1982, the audio CD has become the dominant format for high-fidelity recorded music. Digital audio data can be converted to analog form to reproduce the original audio signal (see digital-to-analog conversion). Coinvented by Philips Electronics and Sony Corp. in 1980, the compact disc has expanded beyond audio recordings into other storage-and-distribution uses, notably for computers (CD-ROM) and entertainment systems (videodisc and DVD). An audio CD can store just over an hour of music. A CD-ROM can contain up to 680 megabytes of computer data. A DVD, the same size as traditional CDs, is able to store up to 17 gigabytes of data, such as high-definition digital video files
This describes the media used by CD-ROM players The data on a compact disc are encoded as a series of dips and raised areas These two states represent binary data the same number system used by microprocessors The CD-ROM player shines a laser beam onto the surface of the disc and measures the light that is reflected back The intensity of the light that is reflected back enables the player to distinguish individual binary digits See CD-ROM