what is icloud?
iCloud stores your music, photos, documents, and more and wirelessly pushes them to all your devices. Automatic, effortless, and seamless(无缝)— it just works.
Comes with every new Apple device.
Every new iPhone, iPad, and iPod touch comes with iOS 5. And every new Mac comes with OS X Lion. Which means the new Apple devices you purchase are all ready for iCloud, right out of the box.
Simple to use. Simple to set up.
iCloud is easy to use, and setting it up is no exception（例外）. It takes only a few steps before all your important stuff （重要的东西）is up to date（更新） on your iPhone, iPad, iPod touch, Mac, and PC
how to set up iCloud ? just follow next steps
1:Make sure your device is running iOS 5.
To update to iOS 5, just connect your device to your Mac or PC and follow the onscreen instructions in iTunes.
2:Turn on iCloud.
When you turn on a new iOS device or after you’ve completed the update to iOS 5, follow the instructions in the setup assistant to activate your device and set up iCloud.*
If you skipped the setup process, tap the Settings icon on the Home screen, select iCloud, and then enter your Apple ID.
3:Customize your settings.
Tap the Settings icon and select iCloud. Tap the On/Off switches to enable individual(个人) iCloud services. To enable iCloud Backup, tap Storage & Backup and switch on iCloud Backup.
Free iCloud email account.
With iCloud, you can get a me.com email account that’s ad-free, is up to date everywhere you check it, and includes webmail at icloud.com. Just turn on Mail in iCloud settings and follow the onscreen instructions.
4：Enable Automatic Downloads in Store settings.
To enable automatic downloads for your music, apps, and books, tap the Settings icon on the Home screen and select Store.
Your content. On all your devices.
iCloud is so much more than a hard drive in the sky. It makes it quick and effortless to access just about everything on the devices you use every day. iCloud 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, movies, 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.
Free gets you a lot.
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, movies, apps, books, and TV shows, as well as your Photo Stream, don’t count against（计入） 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.
The apps you use every day are ready for iCloud.
When you update your iPhone, iPad, or iPod touch to iOS 5, your favorite Apple apps become seamlessly integrated with iCloud. Just like that. So all your content and information is available and up to date, no matter which device you’re using.
[iCloud for photo stream]
With iCloud, when you take a photo on one device, it automatically appears on all your other devices. No syncing(同步). No sending. Your photos are just there. Everywhere you want them.
1：Your photos everywhere. In a flash.
Take a photo on an iOS device. Or import a photo from your digital camera to your computer. iCloud automatically pushes a copy of that photo over any available Wi-Fi or Ethernet connection to the Photos app on your iOS devices, iPhoto or Aperture on your Mac, and the Pictures Library on your PC. You can even view your Photo Stream album on your Apple TV. So you can show off your shots to friends and family from whichever device you’re using at the time.
2：1000 of your latest photos. With you all the time.
iCloud manages your Photo Stream efficiently so you don’t run out of storage space on your iPhone, iPad, or iPod touch. If you have Photo Stream enabled on your iOS device, every single photo you take appears in a special Photo Stream album that holds your last 1000 photos. You can delete any photos you don’t want from the Photo Stream.1 To touch up a photo or keep a favorite shot permanently（永久）, simply save it to your Camera Roll（相机胶卷）. iCloud stores new photos for 30 days, so you have plenty of time to connect your iOS device to Wi-Fi and make sure you always have your most recent shots handy（方便）.
Master photo library. On your Mac or PC.
Keeping a complete set of your photos on your Mac is as simple as turning on Photo Stream in iPhoto or Aperture. Every new photo you take appears in a Photo Stream album just as it does on your iPhone, iPad, and iPod touch. But since your Mac has more storage than your iOS device, it automatically imports every picture from your Photo Stream into your photo library so you can edit, delete, and share the ones you want. Want to get the photos you’ve taken on your point-and-shoot or DSLR camera into your Photo Stream to view on all your other devices? The photos you import to your library from a camera or SD card are automatically uploaded to your Photo Stream. If you have a PC, you can auto-import and upload pictures, too. Just turn on Photo Stream, grab a camera, and start shooting.
Make your photos a big deal with Apple TV.
With Photo Stream and Apple TV, you can view your recent photos on your HDTV for some truly entertaining reality television.2So you can, say, take pictures during your daughter’ssoftball game, then watch a photo play-by-play with the family gathered around the big-screen TV.
Stream photos to Apple TV
Apple TV lets you stream your recent photos from iCloud and view them on your HDTV.