Just to backtrack a little. A music CD comes with music with all the information it's ever gonna have. It is stored in digital form similar to but not exactly the same as WAV files.
WAV (wave) files have the same kind of information as the CD music, again, in it's most memory hogging form.
An mp3 is a distillation of the music in a compressed form, typically 1/10th the size of the WAV files. However, an mp3 file is DATA.
You can play mp3 files on your computer with a program such as 'winamp', which is free to download, and, of course, portable mp3 players. There are also some very nice and inexpensive music personal CD players and boomboxes which will play mp3's burned on to CDs. Typically you have to be careful how you label the mp3's (on the computer) so the boombox will understand them. The manual will explain this. Mine requires me to have 3 digit track numbers such as 001, 002, etc. or it won't recognize 'em.
If you burn mp3 files onto CDs to be played AS mp3s, then you burn a DATA CD. This can be used to move the mp3s from computer to computer, or played on the specialized CD players I mentioned.
If you burn mp3 files onto CDs to be played as an audio CD in a regular music player not as mp3's, then you burn the CD as an AUDIO CD. The program will then 'expand' the mp3 data into a WAV format so that a regular audio (non mp3) CD player can play them. When you do this, you lose the space saving advantage of the mp3, because the WAV format takes up a lot of room. And obviously, the audio CD played from an 'expanded' mp3 will sound the same as the mp3. If you gave up noticeable quality when the original mp3 was made from the original music source, you won't get it back by converting the mp3 back to a WAV. You get playability on an audio CD player, period.