CD-RW

Stands for "Compact Disc Re-Writable."

CD-RW is the rewritable compact disc format. A rewritable CD can be written to, erased, and re-written hundreds of times. One disc can store up to 700 MB of data or 80 minutes of digital audio. Rewritable discs may not play correctly in all CD players, as the rewritable layer on the underside of the disc is not as reflective as the pressed layer on a CD-ROM. Writing to a CD-RW disc requires a compatible disc drive that supports rewriting optical media.

Once data is written to a CD-RW disc, it is read-only and cannot be edited; in order to to make any changes to the files on a disc, it must be erased and re-written. This process makes the format a poor choice for storing files that need to be frequently modified. Instead, the rewritable discs are better suited for frequent data backups, although the format's small capacity compared to DVD±RW discs limits that use as well.

An optical disc drive that can write discs has three lasers—a low-power laser that reads data, a medium-power laser that erases rewritable discs, and a high-power laser that burns data to a disc. A CD-RW drive burns a series of spots onto a reflective layer of a phase change metal alloy on the underside of the disc. At first, this metal alloy exists in a crystalline form that lets light through. A high-power burning laser heats the alloy past its melting point, which then turns opaque as it cools. These opaque spots encode digital data that the reading laser in the drive reads and decodes. When it's time to erase a disc, the drive uses the medium-powered erase laser to heat the alloy layer to its crystallization point.

Updated November 4, 2022 by Brian P.

quizTest Your Knowledge

Which component determines the storage capacity of an Ultrabook?

A
SSD
0%
B
CPU
0%
C
FPU
0%
D
RAM
0%
Correct! Incorrect!     View the Storage Capacity definition.
More Quizzes →

The Tech Terms Computer Dictionary

The definition of CD-RW on this page is an original definition written by the TechTerms.com team. If you would like to reference this page or cite this definition, please use the green citation links above.

The goal of TechTerms.com is to explain computer terminology in a way that is easy to understand. We strive for simplicity and accuracy with every definition we publish. If you have feedback about this definition or would like to suggest a new technical term, please contact us.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe or change your frequency setting at any time using the links available in each email.

Questions? Please contact us.