iCloud will automatically sync a user's iPhone, iPad and iTouch devices. (Justin Sullivan/Getty Images) iCloud will automatically sync a user's iPhone, iPad and iTouch devices. (Justin Sullivan/Getty Images)

Apple CEO Steve Jobs unveiled iCloud at the Worldwide Developers Conference (WWDC), saying that it was the company's "next big insight".

The service is designed to work with the company's iPad, iPhone and iTouch devices and its purpose is to automatically syncs contacts, calendars, photos, videos, e-mails and other content across multiple devices.

Prior to this the only way to share content across devices was to connect the device to a PC or Mac, transfer the information to that machine and then onto the other device.

"Today it is a real hassle and very frustrating to keep all your information and content up-to-date across all your devices," said Steve Jobs, Apple's CEO. "iCloud keeps your important information and content up to date across all your devices. All of this happens automatically and wirelessly, and because it's integrated into our apps you don't even need to think about it-it all just works."

iCloud can also automatically sync paid for content that has been purchased on one device to all of the users other mobile devices at no extra charge.

Apple's new service will compete with Amazon and Google's own similar services known as Cloud Player and Google Music Beta, which were launched earlier in the year. For music content iCloud also offers a service called iTunes Match. This automatically determines which songs, regardless of how you got them, in your collection are available in the iTunes Store.

Any music with a match is automatically downloaded to the iCloud library for you to listen to anytime, on any device. The only music that you then have to upload to the iCloud service are the songs that iTunes doesn't have in its database, which presently consists of 18-million songs.

For music storage iCloud presently costs US $24.99 annually for 20,000 songs. Amazon's competing service charges US $50 annually for 5,000 songs and $200 for 20,000 songs.