With the release of iCloud, all of your Apple Devices are connected as never before. But what if you don't want to just use Apple for your computing?

Before Steve Jobs died, he made a very strong statement at the Worldwide Developers' Conference keynote in San Francisco: "We're going to demote the PC and the Mac to just being devices," he said. "We're going to move your hub, the centre of your digital life, into the cloud."

He was taking about the introduction of iCloud, a service that will automatically update all your Apple documents and iTunes purchases across your suite of Apple devices. Download a track from iTunes on your iPhone and it will be waiting for you on your Mac. Take a picture on your phone and you can show people the result almost instantly on your iPad. Start a presentation in Keynote at home and it will be waiting on your work Mac.

It uses the almost-always-connected nature of these devices in an integrated way. As Jobs said, "Today it's a real hassle and very frustrating to keep all your information and content up to date across your devices. 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 your apps you don't even need to think about it – it just works."

There should, however, have been a caveat to this. He was only talking about iOS devices – iOS 5 specifically. Poor old iOS 4 and Snow Leopard users aren't part of Apple's new iCloud gang, and neither are those who don't use Apple's software on their PCs.

Apple has always enjoyed ring-fencing its content to its own software and devices, and the iCloud experience is only for the iTunes set. If you have an Android phone, you won't be using any of these new services any time soon.

Similarly, although you can get iCloud support for iTunes on your PC, this isn't the same as just logging in to a browser-based version. You won't be able to listen to your music at work if your IT department won't let you install iTunes on your office desktop machine, for example.

Apple-only documents

iCloud isn't like Amazon Cloud Drive, Dropbox or SugarSync, which will let you back up anything. Only files created by iCloud-supporting applications will be synchronised to all your devices.

Neither is iCloud as free and easy as other cloud storage apps, which usually offer browser versions that let you download any of your files by logging into a website. Although there's a website for Apple's service at icloud.com, this just lets you see your mail, contacts and calendars.

You can't stream your entertainment content from the site – instead it's more of a backup for when things go wrong, giving you access to Apple's Find My iPhone service or merely letting you use the site to upload documents created on iCloud-enabled apps like Pages, Numbers and Keynote, not edit them online.

Of course, if you only use the latest Apple devices, these issues won't worry you and iCloud will be a fantastic free extra that puts the cloud to work for you. Some of the services are really fun and useful.

Take Photostream for example, the newest version of which takes the last 1,000 photos from your Apple device, saves them online for you to see on iCloud, and downloads them to all your devices when you switch them on. It will also let you pause supported games on your iPad and then continue later on your iPhone.

The free 5GB of iCloud storage for mail, documents and other backups isn't to be sneezed at, although it's not as generous as some other companies' offerings. That said, this limit isn't affected by any content bought from iTunes, so your Apple-bought music, apps and books are stored separately. Photostream photos don't count towards this 5GB, so the offer is more generous than it first seems.

Your music in the cloud

Some iCloud services are available in the US, but have yet to make their way to the UK. These include iTunes in the Cloud and iTunes Match.

iTunes in the Cloud lets you re-download previously bought content on to your newer gadgets at no additional cost, so everything you've bought is available on all your devices. iTunes Match will scan your entire iTunes library and replace each song not bought via iTunes (music you have ripped from a CD, for example) – even low bitrate versions – with 256kbps, DRM-free AAC versions. These can then be downloaded or streamed to all your other iOS5 products, basically putting your entire music library onto all your Apple devices.

iTunes Match is a subscription service. Unlike Google Music, which is free, Apple charges $25 (about £15) annually to upload and store music not purchased through iTunes. On the other hand, it's a very fast service compared with Amazon and Google's offerings – backing up your entire collection will take hours rather than days.

No song is excluded either; you can manually upload any song not listed in the 20 million-strong iTunes library. Another unusual thing about iTunes Match (which may mean it will take a while to get to the UK) is that Apple has obtained permission for the service from all the major music labels. Google and Amazon have gone for a more 'suck it and see' approach, describing their services as hard drives in the cloud and not seeking permission for the content – or only striking a deal with some labels.

Google and Amazon argue that the tunes are just data, but it could be said that Apple is on a more sound legal footing. It wouldn't be fun to upload your collection to Google or Amazon and then have access denied due to a legal ruling.

The death of MobileMe

It's no secret that Apple has a poor record when it comes to cloud computing. iCloud started as iTools in 2000, and became a much-mocked subscription service called MobileMe in 2008.

MobileMe is now being discontinued, to the chagrin of some dedicated users, with subscribers being transferred to iCloud. They are gaining all its new services, but losing some older MobileMe-only ones like the Gallery, iDisk, and iWeb publishing services.

Although iCloud is a revolation compared to these earlier offerings, Apple still isn't exploiting the full power of cloud computing. For Apple it's all about the content – films, books, TV and music. Microsoft and Google are all about online collaborative services, where people use the cloud not just for syncing, but for shared document creation online, while Apple has stuck to using it for content delivery.

The cloud means you no longer have to plug your iPad into your Mac to update it – it happens automatically and out of sight. This is admirable, but leaves a big hole in its functionality. Where are the online versions of Pages, Notes and Numbers? Why can't people collaborate on these programs using the cloud?

Anyone who needs this kind of service has to go to another company for it, and it may yet be to the detriment of Apple. In fact, it's already starting to show – Microsoft boasted that in November 2011, Hotmail was being used on two million iOS 5 devices, and was growing by 100K users per day. This may change once the full impact of iCloud is felt, or may be due to legacy use as more people switch to Apple from Microsoft devices, but Apple should be worried that people are sticking to its competitors' services.

A restricted hard drive

At the iCloud launch, Steve Jobs noted that "a lot of people think the cloud is just a hard drive in the sky." Clearly a lot of people do, and with iCloud Apple has challenged this idea by using it to store Apple-only documents.

Integration is key to true cloud computing; no one company can provide everything you want to do on a computing device. There has to be an opening for other company's technologies or people start to look elsewhere for a less restrictive service. This is a common complaint levelled at Apple.

The cynical see iCloud as just another way to encourage people to just buy more Apple devices, but is that really any different to the ring-fencing demonstrated by Amazon's Kindle Fire, or the bundling of all of Google's services from your Google home page?

Admittedly, the limits are a lot more delineated with iCloud, but if you have more than one iOS 5 device, there is little doubt that the convenience offered by iCloud and its associated services will be very attractive. If you only use Apple hardware and software, iCloud will give you everything you need.