Q: aiff vs. wav

hi folks websearches havent been able to answer this for me and ive been deleting many emails, so unsure if covered here before... i have an imac when duping a cd, in terms of "highest-end" audio quality, is it preferable to import using .wav or aiff? thanks feel free to answer offlist if you think of minor interest to list much obliged steve koenig n.p.: elliot carter opera/ what's next' /ecm jumpartsjournal.org