What is iCloud? Behind Apple’s mysterious but essential service

We hear a lot about iCloud being a cloud storage and cloud computing service, but what does that actually mean?

Cloud services like iCloud give you a way of storing data and synchronising it with other computers and devices on the internet. Your files are all stored securely on Apple’s servers, under lock and key by being linked to your own Apple ID and password. Only the devices you’ve authorised have access to the data you’re sharing in iCloud – no one else.

iCloud can be used to store your Photo Stream – a collection of the last 1,000 photos you’ve taken over the previous 30 days (regardless of device), so you can quickly find images you want without having to worry about which computer or device they were taken from.

It can serve as a repository for data backed up from your phone, your iPad or your Mac, including data settings and information about which apps you’ve installed on what device (though the apps themselves aren’t backed up). iCloud can also be linked up to an email account.

Apple offers online versions of its iWork apps – Pages, Numbers and Keynote – so you can work on files from a web browser regardless of whether you have access to a Mac or an iOS device, and then return to working on the same files when you have your Mac or iOS device again.

All this functionality and all these capabilities are maintained on banks of computers that Apple maintains in central locations, which are accessible wherever you are on the internet. iCloud is a resource shared with hundreds of millions of other subscribers, all with the same access as you.