Being that we are a Mac family, 2 iPads, an Airbook, and an iMac, I am trying to decide to use iCloud or not. My wife's pad is 16GB so I don't want to overload whatever she may have remaining. Does iCloud work like Dropbox? i.e. store stuff there and access at will from whatever device. Or does iCloud stream and place copies of photos, docs, music, etc on each device? I'm really sorry for such a basic question, but in all the reading I've done, I just really don't understand how it works. Thanks.