Differences Between CDR & CDRW

Compact Discs are laser-optical media used to store digital data. CD-recordable discs can be written to only once. CD-rewritable discs can be written to and erased multiple times.

History

CD technology was introduced in the 1980s, but CD burners that could write to CD-Rs did not become viable for the consumer market until prices dropped below $1,000 in 1995. CD-RW technology was introduced in 1997.

Function

CD-R discs are used to store permanent or final copies of data such as music, backup copies of software installation CDs and backups of unused files. CD-RW discs usually are used to store temporary copies of data such as draft versions of documents and backups of frequently modified files.

Identification

CD-R and CD-RW discs usually are clearly labeled on the non-writable side of the disc. The writable side of a CD-R typically is blue or green though other colors are common. The writable side of a CD-RW is dark silver or charcoal grey.

Comparison

Both types of discs are available in 650 MB and 700 MB capacities. CD-R discs are less-expensive, feature faster write speeds and have longer expected lifespans than CD-RW discs.

Potential

For general data storage, CD-R and CD-RW discs are widely used. Newer, smaller, faster and higher-capacity technologies such as DVD discs, portable hard drives, flash drives and Internet storage and backup services have gained in popularity and may eventually make CD media obsolete.

References

• The history of the CD
• Understanding CD-R & CD-RW
• Should We Really Be Writing the Obituary For Optical Media?