There are a lot of people who are aware that .mp3 and .wav are known to be two file formats that will allow people to listen to music or sounds that they like. One main difference between the two is when you say .mp3, this means that the file is compressed.
When you see the .wav, this means that the file is not compressed. You can use WAV files when you would like to do some editing like editing podcasts. You would use the .mp3 files when you would like to do file sharing.
This is the reason why most of the sound files that you will get are in .mp3 form especially when you would like to download them.