compact disc recordable (CD-R)
The CD-R format of a recordable compact disc (CD), described in the Orange Book, is used for storing audio and data. It can be played in CD players and CD drives.
The CD-R can be written once using a CD recorder and succeeds the WORM. The CD-R format is compatible with CD-DA and CD-ROM/XA.
In terms of structure, the CD-R is more complex than the CD-ROM. It consists of a carrier layer of polycarbonate, on which a light-sensitive, translucent layer is applied. On top of this is a reflective gold layer and the protective layer. During burning, a high-energy laser beam discolors the light-sensitive layer, thus changing its reflective properties.