The iCloud...

iCloud stores your music, photos, documents, and more and wirelessly pushes them to all your devices. Automatic, effortless, and seamless....

Every new iPhone, iPad, and iPod touch comes with the  iOS 5 and every new Mac that is manufactured comes with OS X Lion which means they are already configured for iCloud.

iCloud is also easy to set up and use, it takes only a few steps before all your important stuff is up to date on your iPhone, iPad, iPod touch, Mac, and PC. Learn how to set up iCloud

iCloud makes it quick and effortless to access just about everything on the devices you use every day. It automatically and securely stores your content so it's always available to your iPhone, iPad, iPod touch, Mac, or PC.
It gives you access to your music, apps, latest photos, and more from whichever device you happen to be using. And it keeps your email, contacts, and calendars up to date across all your devices. No syncing required. No management required. In fact, no anything required. iCloud does it all for you.

When you sign up for iCloud, you automatically get 5GB of free storage. And that’s plenty of room, because of the way iCloud stores your content. Your purchased music, apps, books, and TV shows, as well as your Photo Stream, don’t count against your free storage. Since your mail, documents, Camera Roll, account information, settings, and other app data don’t use as much space, you’ll find that 5GB goes a long way. And if you need more storage, you can easily purchase a storage upgrade right from your device.

source

check out this video about iCloud.....