The audio file type is very important if you plan on using it in another project like in Premier or other programs. When exporting a Mix-down or pure audio file from any DAW it will export as a .WAV file. The .WAV file type is very useful for sending tracks to other producers that may want the raw audio file or want the highest quality file. However .WAV files are really hard for any music player to play.
The other file type is .Mp3 it is a slightly lower quality file type but it is a way more acceptable file types to other programs or music players..Mp3 files would be used if you planned to share it to media sharing websites such as Sound Cloud or YouTube. This also makes the audio editable in programs like premier for making a quality sounding video performance.
For more information you can refer to the video below.