Apple released iTunes Match, their iCloud-powered music locker service, into beta yesterday and immediately -- and rightly -- it's been Zapruder-ed by every eyeball online, especially when it comes to whether it downloads music, streams it, or both. And confusion and conflation have followed.
Sure, technically there's a difference between downloading a song to your local iPhone, iPod touch, iPad, or Mac or Windows PC and playing, and streaming that song directly to your device from iCloud. But many downloads will start playing before they finish and most streams will cache locally to prevent hiccups due to the ever present irregularity of internet connections. The lines are blurry, and made even blurrier by the music industry who wants to nickel and dime Apple, and consumers, at every turn.
(It's fair to say that if the music industry acted 20 years ago the way they act now, CDs would have been licensed per-player. You want to play that CD you bought in your car and in your living room? Pay us again! You want to play it in your bedroom? PAY US!)
As it stands, Apple technologically and no doubt contractually doesn't want anyone to know or care about whether or not iTunes Match downloads or streams from iCloud. The same way Apple doesn't discuss things like RAM, my guess is they're not going to specify exact behavior for iTunes Match.
You'll hit "play", Apple will take care of managing the local/iCloud relationship. Just like they don't think my mom should have to worry about file systems on iPad, they probably don't think she should have to figure out download vs. stream. It should just work.
Once iTunes Match is stable and out of beta, no doubt every geek and their packet sniffer will pour over it, parsing out every nuance of the stream vs. download behavior, and keep us updated when Apple tweaks it and makes changes to it going forward.
Meanwhile my mom won't worry about whether or not she's synced the Lion King Musical soundtrack, or how many GBs she has left. She'll just hit play and listen.
(Or she would if they released the damn thing in Canada.)