Yesterday, Apple has officially unveiled its new cloud service iCloud at the 2011 Worldwide Developer Conference (WWDC).

Steve Jobs, chief executive officer of Apple, took the stage and introduced the new service to the crowds.

Here are 10 features of Apple's iCloud that you need know to keep up with this new service.

1) iCloud allows users to store data, as well as acting as a server for email, calendars, contact lists and similar products.

2) iCloud will support up to 10 devices for free,

3) iCloud includes 5GB of free cloud storage for mail, document storage and backup.

4) iCloud service for non-iTunes music will be $24.99 per year.

5) The iCloud service will automatically push a purchased song to all of your devices.

6) Everyday, iCloud backs up iOS-based devices over Wi-Fi, allowing users to restore their exact settings and content onto a new iOS based device.

7) Customers who purchased the tracks and albums from iTuneswill be able to re-download them from the cloud to other iOS-based devices without paying extra fee.

8) Customers can turn on a feature that automatically downloads a copy of content to other devices

9) A new app called Photo Stream will keep photos synchronized across devices along with iCloud. It automatically stores the last 1000
photos, and then anything you want permanently; you just need to move them to an album. And it will be stored for 30 days in iCloud.