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A CD-RW drive can write about 700MB (not MiB) of data to CD-RW media an unlimited number of times. Most CD-RW drives can also write once to CD-R media. Except for the ability to completely erase a disc, CD-RWs act very much like CD-Rs and are subject to the same restrictions; i.e., they can be extended, but not selectively overwritten, and must be closed before they can be read in a normal CD-ROM drive. A variation of UDF formatting allows CD-RWs to be randomly read and written, but limits the capacity to about 500MB.

Note that unlike CD-Rs, CD-RW discs are non-standard, in that they do not meet the Orange Book standards for CDs. Hence CD-RW media cannot be read by CD-ROM drives built prior to 1997 due to the reduced reflectivity (15% compared to 70%) of CD-RW media. CD-RW is also more expensive than CD-R, and so CD-R is sometimes considered a better technology for archival purposes. The write-once nature of CD-Rs also ensures that data cannot be accidentally modified or tampered with, and encourages better archival practices. However, due to the crystalline layer of CD-RWs (as opposed to the organic material used in CD-Rs), disc manufactures claim longer durability and better data safety of CD-RWs.

1 See also

• computer storage
• computer hardware
• disk or disc
• DVD-RW
• DVD+RWA DVD+RW is a rewritable optical disc with equal storage capacity to a DVD+R, typically 4. 7 GB (interpreted as ≈ 4. 7 · 109, actually 2295104 sectors of 2048 bytes each). The format was developed by a coalition of corporations, known as the DVD+RW.

2 References

3 External links

• The CD-R FAQ