Just a quick comment
With Toast, you have the option of "burning a session"or "burning the disk".
If you "burn the session" (ie other sessions have left space or room on the CD-R or DVD-R) you can come back and add more info (data), but when you put that burnt CD into your drive you will have 2 (or 3 or whatever) disks appear on your desktop). A good way to use a CD.
If on the other hand you "burn disk", it finishes (or closes it off) the disk off and you can no longer write to it. So even if you only use 50MB out of 700 MB you lose it.
I am not sure about audio CDs, but am aware to play correctly, for some reason they usually need to "close off the session". I gather that is simply burning some info into the CD that indicates the structure and length of the files (data/music) on it.. a little like an index at the beginning of a book, it is not created (or written) untill the book is finalised. That now actually makes sense to me 🙂
Have a good day
Roy