Thanks to the combination of iTunes 10.5, iOS 5, and iCloud, you can sync data wirelessly with your iOS device. In fact, there are two ways to do so: iCloud syncing, which sends specific information to and from Apple’s iCloud servers over an Internet connection, and Wi-Fi Sync, which syncs your device with iTunes on your Mac via your local wireless network.
But there are notable differences between what gets synced using each method—some things are exclusively iCloud or Wi-Fi Sync, while other things can be synced via either method. And it’s important to note that Wi-Fi sync and iCloud sync aren’t mutually exclusive. You can, and mostly likely will, use both methods depending on the situation and your settings. Which is why it’s easy to get confused about the differences and similarities between the two.