Mmm good question. A friend of mine asked this and here I am to answer it.
Well when you burn a cd with a utility like Nero then you have to select if it is a Data or an Audio cd. If you select data cd then your mp3 will be burned as is in the cd.
But then the problem is that if you want to play this on a regular cd player you simply can’t. Your cd player cannot read mp’s but only audio cd’s.
So select Audio Cd and when inserting mp3’s in your compilation Nero or whatever utility you use will convert them automatically to cda format (the format which is recognized by the cd players).
Now your regular cd player can play the and you can enjoy the music almost everywhere. If you have questions too don’t hesitate to ask me.
photo credit: jcolman