CD-RW are rewritable discs, i.e. you can record on then over and over again, as opposed to CD-R, which you can record on once only.
Some machines play back CD-RWs, but you have to make sure the disc is 'finalised', which is something your software should be able to do. I have found that CD-Rs are playable on more machines than CD-RWs, so, as they are relatively cheap, I tend to stick to those, Lona, but that's just my preference.
I expect Adept will be along soon to tell you I'm talking crap again!!