CD-R (Compact Disc-Recordable) was shown to the world for the first time in 1988 and is a write Once Read Many (WORM) optical format that can be written too on several occasions.
A standard CD-R is a 1.2 mm in thickness with a 80mm or 120mm diameter. This polycarbonate disc contains a spiral groove, called the "pregroove" to guide the laser beam upon writing and reading information. The bottom side, which faces the laser beam in the player or drive, is flat and smooth.
Although the CD-R was initially developed in Japan, most of the production of CDRs had moved to Taiwan by 1998, and also to other parts of asia. Taiwanese manufacturers supplied more than 70% of the worldwide production of 10.5 billion CDR's 2003