AIFF is Apple’s uncompressed, lossless audio format and offers audio quality comparable to WAV while supporting metadata more consistently.
The audio inside an AIFF and a WAV of the same master is identical, and so are the file sizes. The difference is entirely in how well they carry information about the track: AIFF handles embedded artwork, artist, title, comments and key fields reliably, where WAV’s tag support is patchy and varies between programs.
That makes AIFF the better pick when you want uncompressed audio and expect the tags to survive moving between software or machines. It comes from the Apple world, but support is broad regardless of platform and it appears on every major supported-format list, including rekordbox, Serato and Traktor. Like WAV it exports to USB without the restriction that affects FLAC, and the same sample rate caveat applies: 88.2 and 96 kHz files only play on newer media players, so keep 44.1 kHz for anything you might hand to unfamiliar gear.
As with WAV, the honest question is whether you need uncompressed at all, since FLAC gives you the same audio in roughly half the space. The case for AIFF is that it is the lossless format you can actually rely on in a club booth.
See Also
WAV, Lossless Audio, and file format