Are CD's re-writeable?

[catkingirl]

At work we have'Toast' a CD writing/copying package - can I delete stuff on existing discs and use them to store other data? How would I delete it - if at all this is possible? Thanks.

[rekstout]

There are three different types of CD (as used for coputer data storage) CD-ROM, CD-R and CD-RW.

A CD-ROM is read-only - data cannot to overwritten, altered or added to.

A CD-R can be written to once and once only (to do this you will need a CD Writer drive)

A CD-RW can be written to and overwritten again and again (about 10,000 times) (again you will need a CD Re-Writer drive for this). The CDs one gets through the post or in magazines from the likes of AOL are useless for re-use. CD-RWs can cost as little as GB�2 each nowadays and are a cheap and effective storage medium.

[catkingirl]

We have CD-R disks - thats very helpful, thanks!

[lisaj]

This is almost true: If a CD-R has not been 'finalised', then it can be added to or entirely re-written from a data point of view. What must be remembered is that the physical disk cannot be erased, so if you've used 300Mb of a 600Mb disk and not finalised it, you'll only be able to write it again with a maximum of 300Mb of data...