What is AIFF?

Apple's uncompressed format, the Mac counterpart to WAV, and still what Logic and older Pro Tools sessions expect. Its one genuine oddity is storing the sample rate as an 80-bit extended float, a data type almost nothing else in computing still uses.

What is WAV?

Uncompressed audio, roughly 10MB a minute, and the format every piece of audio software will accept without complaint. Nothing is compressed and nothing is lost, which makes it the right thing to edit and the wrong thing to email.