What is CD-RW?
CD-RW is CD-ReWritable, previously called CD-Erasable. It is a new optical disc specification baptized by the industry organization OSTA (www.osta.org). Basically, where CD-ROM was Read Only (RO) and CD-R is Write Once, Read Many (WORM), CD-RW is Read and Write and Overwrite (erase) access to an optical disc. So CD-RW could be considered a superset of CD-R functionality. CD-R and CD-RW media are not the same as CD-ROM media, because the contents of the disc must be writable by a laser. Furthermore, CD-R and CD-RW media reflectivity is lower than CD-ROM media. Hence, CD-R and CD-RW media may not be readable by every CD-ROM drive. Multiread is the new specification for any optical drive to read the new CD-R and CD-RW media, vendors are begining to adopt it into CD-ROM drives. CD-RW drives are SCSI devices that can function as a CD-ROM as well as a hard drive. Thanks to Mark Lavi
Once informally dubbed “CD-Erasable,” CD-RW is the official acronym for CD-ReWritable. CD-RW uses a phase-change technology that allows a drive’s laser to change the state of the recording layer and thus the physical properties of a disc in order to write and rewrite data to the same disc. CD+RW is a slightly different physical recording format supported by certain drive hardware, but the discussion here applies to both CD-RW and CD+RW.
