Apple's Steve Jobs today announced the Apple iCloud, and demoted the PC to 'just another device' status. The iCloud is a connected, hosted account that stores all files and communications in a single place, accessed from multiple devices.

In short, iCloud stores your content in the cloud and wirelessly pushes it to all your devices, according to Apple. iCloud launches in the Autumn at the same time as the iOS 5 upgrade.

The iCloud means, according to Jobs, that the PC is demoted to being just another device, like a phone, tablet or MP3 player. Using iCloud, a user of any of these devices can access all of their photos, music, video and so on, wherever they are. And you can access the iCloud from all iOS and Mac OS devices, but also from Windows PCs.

He said: "We've got a great solution for this problem. And we think this solution is our next big insight. We're going to demote the PC/Mac to be just another device."

See also: Apple announces Mac OS X 10.7 'Lion' - full details

If you are working on a document in Pages, Numbers, and Keynote, you can save it to the cloud, and access it from any other device you have with those programs. Apple is also releasing iCloud Storage APIs so that app developers can utilise this functionality.

For users, pictures are now in the cloud and pushed down to devices automatically, Jobs said. Users can access all photos from all devices, and Apple will store the most recent 1,000 photos on iCloud for 30 days. To save them permanently, you simply save them to a new folder.

When you make a new contact on your iPhone, it's automatically stored in the cloud, and then it's automatically pushed down to other devices. It's a similar story with calendars. Users have to do nothing other than sign in. iTunes music files brought from the iTunes store are available to all your devices - but not music ripped from CDs. You can match these to songs in the iTunes store, however, in a process called iTunes Match that Apple claims takes minutes, and offers the same 'rights' to those music files as songs purchased from iTunes. iTunes Match will cost $25 a year in the States.

Wireless backup to the cloud has been added, so iPhone and iPad users can be PC free. Once a day a lot of important content is uploaded to the cloud. If you ever get a new phone, you simply type in your apple ID and password and everything will be loaded on that phone automatically.

Users can access iCloud simply by buying a new phone or upgrading. Simply login, and it's on by default, although you can turn it off. You get 5GB of free storage, and can pay to upgrade.

Introducing the keynote, Steve Jobs said: "We're going to talk about three things today. If the hardware is the brain and the sinew of our products, the software is their soul."

The WWDC keynote in San Francisco was attended by more than 5200 attendees and, according to Apple, sold out within two hours.

Full coverage of the WWDC keynote's Jason Snell and Dan Moren contributed to this story.