WAV is to audio as BMP is to images: the fundamental, brutal, unsophisticated, first-effort approach that also, coincidentally, because of its brutality, somehow simultaneously represents an apex of fidelity and impracticality.
All other image formats get parsed to recreate either an identical or approximate bitmap as would have been encoded into the BMP file, but usually with more features or smaller size, or both.
All other audio formats get parsed to recreate either an identical or approximate audiowave as would have been encoded into the WAV file, but usually with more features or smaller size, or both.