# How do CD-RW disks work?

**URL:** https://boards.straightdope.com/t/how-do-cd-rw-disks-work/593706
**Category:** Factual Questions
**Created:** [August 22, 2011, 10:11pm UTC](https://boards.straightdope.com/t/how-do-cd-rw-disks-work/593706 "2011-08-22T22:11:36Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)
#### Post date: [August 22, 2011, 10:11pm UTC](https://boards.straightdope.com/t/how-do-cd-rw-disks-work/593706/1 "2011-08-22T22:11:36Z")

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I heard it explained that, when you rewrite a CD-RW, the drive burns new tracks leaving the old tracks behind. But, is that to say the disk is not really erased? Instead, might it burn over the same tracks to wipe out the old data, or would that only corrupt the new data? Surely, someone on the SD can explain this…and, is there a limit to how many times you can rewrite a disk?

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### Author: ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)
#### Post date: [August 22, 2011, 10:31pm UTC](https://boards.straightdope.com/t/how-do-cd-rw-disks-work/593706/2 "2011-08-22T22:31:40Z")

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> **[How do CD-RWs rewriteable CDs work?](https://electronics.howstuffworks.com/question655.htm)**
>
> Re-writable CD's are pretty amazing things. They were the first tools in the newest generation of personal music production.

Basically, it erases the data by melting the data layer with one laser, then writes new data with a different laser.