"Real" manufactured CDs are produced by molding pits into the plastic substrate (under the clear plastic layer). The laser reads the pits as having different reflectivity from the surrounding flat parts and that's what it interprets as music or data or whatever. CDRs and CDRWs are made with layers of dye that, when zapped by a properly adjusted laser, mimic the reflectivity of the pits. The problem is that the dye layers are not stable, and this leads to unreadable CDRs. I have seen some that looked like oil slicks, and were unplayable. There is no cure for this condition. A study was done last year and Mitsui was found to be the longest lasting CDR brand...but there are no guarantees. You have to be careful to avoid exposure to sunlight and heat. I ALWAYS put CDRs in jewel cases with black backs, even when giving a band a dub of a couple of songs to take home. Otherwise they can deteriorate pretty fast. So the difference between a manufactured CD and a CDR is that the manufactured one is not "burnt": its digital pattern is a physical spiral of pits and it will outlast a CDR by probably about a million to one! I have 4-year-old CDRs that are unreadable, which led me to do some research....If you want to archive, CDRs ain't the way to go.
Note that this is completely apart from the issue of sound. A CDR will sound exactly like a manufactured CD, as long as you have the skill to make your recording that good......