You got it donmunro,
mp3's are wav files that have been converted for optimum internet transfer, while still maintaning a quality sound. When comparing an mp3 to a wav file the mp3 is about 5-10% the size of its wave counterpart, thereby allowing the enduser to download and manage the mp3 much quicker.
Since the standard for most cd's is wav files, you will have to get a mediaplayer/converter. Once the mp3 is on the harddrive you convert it to a wave. At this point you must realize that the amount of space that 1 wave file would take up on your hard drive would be something like 40-50M for a 4M mp3.