After I record a track and put into an audio mixdown and I have options as to which type of file I want it in. My question is whats difference in the files.
To put it in simple terms...

.wav = low compression, higher quality

.mp3 = high compression, lower quality

.wma = windows media audio, usually high compression low quality as well
A .wav file should have no compression. That's why they're huge.

.mp3 and .wma are similar, except that not all formats compress the audio the same way. Also, bit rate matters. A 128k mp3 is going to have lower quality than a 360k mp3. More data = less information lost through compression.
Hi, I'm Peter
mp3 is practically the same as wma, but wma is microsoft's mega hyped up version. wma also ahs the ability to have digital rights encryptions built into the file.