At its heart, iCloud is about making content available on all Apple devices simultaneously without any effort on the part of the user. The mantra “It just works” was repeated multiple times during the announcement. Once set up, device sync will occur automatically in all supported applications.
The apps supported by iCloud include the iWork suite (Pages, Numbers, Keynote), Contacts, Calendars, the App Store, iBooks, and iTunes. Productivity apps like Pages will instantly sync content created on one device across all devices using the same iCloud account. Up to 5GB of content from iWork, Contacts and Calendars can be synced.
The storefront apps, meanwhile, will instantly sync purchases. An app, eBook or song purchased on one device will become available on all devices attached to the same account.
iTunes received particular attention. Apple made sure to argue that its solution is much simpler than Amazon’s, and that an unlimited number of songs purchased from iTunes can be made available on up to 10 devices without any additional charge.
Also announced was iTunes Match, which is Apple’s answer to users who have a large amount of content ripped from other sources. Match can import music from you library and make it available to all devices on an iCloud account.
However, this service does have a price tag of $24.99 per year. Apple was quick to point out that Match will put no limit on the amount of music users can important from their library, making it less expensive than competitors like Amazon Cloud Storage for users with large collections.
Source: Apple WWDC 2011