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Article: Compact Discs
- Article from:
- Dictionary of American History
- Author:
CopyrightCOPYRIGHT 2003 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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COMPACT DISCS
COMPACT DISCS
(CDs) are small, thin, plastic discs twelve centimeters in diameter that contain a metallized surface that holds optically recorded digital information, such as sound, images (still and motion), and computer programs. Data is recorded by creating microscopic pits along a single track on the metallized surface; playback incorporates a red laser beam reflected onto the surface that measures the pits and translates them into binary information. A standard CD can hold between 74 and 82 minutes of audio, or approximately 780 million bytes of data. CDs are nearly unaffected by the number of times they are played. The disc's durable surface tolerates fingerprints ...