CD-RW discs or Compact Disc Rewritable discs are specifically rewritable optical disc formats. At the time of development these were known as CD-Erasable discs and were finally introduced in 1997 after lots of endeavors.

It must be accepted that CD-RW discs never gained the extensive fame (that was perhaps due also) of CD-R, in some degree because of their higher per-unit price along with lower recording and reading speeds, and compatibility issues with CD reading units in addition to between CD-RW formats of different speeds specifications.

There are other reasons as well, as per the analysts. They do opine that the CD-RW format, if compared with other types of rewritable media including Magneto-optical and flash memory based media, Zip drives, makes use of the typical CD-ROM and CD-R file systems and storage strategies. These have been proved to be inapplicable for recurrent modest file additions and deletions, and all these have made the application of CD-RW as a reliable removable disk unfeasible.

In addition, CD-RW does have a shorter rewriting cycles life (ca. 1,000) when compared to almost all of the formerly exposed types storage of media (in general above 10,000 or even 100,000). Well, this is certainly less of a hitch if we take into account that CD-RWs are frequently written and erased in their totality, and not with continual small scale changes, as a result normally wear leveling hardly becomes an issue.

The ideal usage domain of CD-RW discs remains in the creation of test disks, temporary short or mid-term backups, and on the whole, where an intermediary solution between online and offline storage schemes is essential.