Apple iCloud: A visual tour

Backup
Backup takes sync to the next level by backing up your iOS devices to iCloud daily over Wi-Fi when you charge your device. Apple backs up purchased music, apps and books, photos and videos from the Camera Roll, device settings, and app data. The backup is also available when you change your phone; when you enter your Apple ID and password during setup, iCloud restores your items to your new device.
iTunes in the Cloud
With iTunes in the Cloud, you can download music that you previously purchased from iTunes to your iPhone or iPad for free, and new music purchases can download automatically to all your devices. Apple is releasing a free beta version of iTunes in the Cloud for iPhone, iPad, and iPod Touch devices running iOS 4.3. iTunes in the Cloud will support all iPhones that iOS 5 supports this fall.
Photo Stream
The Photo Stream service automatically uploads to iCloud any photos you take with an iPhone or iPad, and wirelessly pushes them to all your devices and computers. If you take a photo with your phone, for example, you can quickly view it on your iPad, without any fuss. You can also view the photos on your Apple TV via a special Photo Stream album stored in iCloud.
New Contacts
iCloud keeps contacts in sync on all connected iOS devices, so you don't have to connect your phone to a computer to get your latest contact updates. When you create a contact on an iOS device, it first joins the cloud, and then it pushes straight away to your other devices.
iTunes in the Cloud, Part 2
It all works when you touch the cloud button: You can see the music you've bought (regardless of which device you bought it on), and you can access your purchase history from the iTunes Store on your Mac, PC, iPhone, iPad, or iPod Touch. iCloud can also automatically download any new music purchase to all your devices over Wi-Fi or 3G.
New Mail
Good-bye, MobileMe. Apple says that it has rewritten the Webmail service for iCloud, which offers a free me.com e-mail address. Mail in iCloud pushes messages across all your devices so that your inbox and mailboxes stay up-to-date on all your iOS devices and computers. Mail in iCloud is ad-free.
Apps in the Cloud
Any apps you purchased will be available for redownload on any iOS device via a purchase-history menu, and you can have iCloud automatically push new purchases to all your devices. iCloud includes 5GB of free cloud storage for Mail, Document Storage, and Backup. Purchased music, apps, and books, as well as Photo Stream content, do not count against the storage limit.
New Calendar
As with MobileMe, the iCloud calendar keeps your events in sync across iPads, iPhones, and Macs. The calendar supports shared datebooks for groups (with changes pushed across the board). Similar to contacts, when you create a new event in your calendar, it first enters the cloud and then pushes to all connected devices.
Apple iCloud unveiled
Announced along with iOS 5 and new details about OS X Lion, Apple's long-awaited iCloud service offers new functionality for iTunes, as well as cloud-based photo, document, and app storage. It's like MobileMe -- but reasonably priced and relevant.
iTunes Match
If you have songs that you ripped from CDs or bought from other stores, iTunes Match will mirror them in the cloud, with over 18 million tracks available. Mirrored songs will be available at 256 kbps, regardless of the original quality. You can also upload manually what Apple can't match. iTunes Match will be available this fall for a $25 annual fee.
iBooks in the Cloud
With iCloud, iBookstore can download purchased books to all your devices, right after you buy them. Like the App Store, iBookstore also allows you to see your purchase history, and tapping the iCloud icon will download books to up to ten devices for free.
Photo Stream Storage
Photo Stream stores the last 1000 photos on each of your devices, and you can save them permanently in an album. Macs and PCs will store all photos from the Photo Stream, since they have more space. iCloud will store each photo in the cloud for 30 days, but it's unclear what happens if you exceed the 30-day limit.
Documents in the Cloud
Included in your 5GB iCloud storage are all documents you create using iCloud Storage APIs, which automatically push to all your devices. When you change a document on any device, the changes automatically push to other iOS devices. Apple's Pages, Numbers, and Keynote apps already support iCloud Storage. You will be able to buy more than 5GB of storage space, with details due to be announced when iCloud ships this fall.