Compact Disk, Compact Disk-Read Only Memory. A data storage medium that uses the same physical formats as audio compact disk. There are several logical formats used to store data on CDs. Compact disk can store (currently, 2003) approximately 700 megabytes of data.

The Yellow Book specifications were so general that there was some fear in the industry that multiple incompatible and proprietary formats would be created. In order to prevent such an occurrence, representatives from industry leaders met at the High Sierra Hotel in Lake Tahoe to collaborate on a common standard. Nicknamed the High Sierra Format, this version was later modified to become ISO 9660. Today, CD-ROMs are standardized and will work in any standard CD-ROM drive. CD-ROM drives can also read audio compact discs for music, although CD players cannot read CD-ROM discs.