Apple temporarily gave MobileMe users 20GB of storage, but it will be revoked on Sept. 30 as part of the introduction of iCloud and the removal of MobileMe.

iCloud replaced MobileMe, Apple's former subscription-for-storage service providing an "@me" e-mail address and the "Find My iPhone" service; an app is now available for the latter. iCloud works across iPhones, iPads, and iPods, and allows app downloads and contacts to be synced. iOS installations and setup can take place over the cloud without connecting to iTunes; the move is part of Apple's "post-PC" era, moving away from the desktop. 

In an e-mail sent to iCloud users, Apple said that a 5GB storage limit will be introduced from Sept. 30, 2012. The e-mail warns users with over 5GB of content uploaded that, unless the new storage limit is met, backups and app uploads will stop. 

Users have two ways to comply with the lower limit, as Apple specified in the e-mail. First, users can head to Settings and then iCloud. Tap Storage & Backup, then Manage Storage, and then delete and/or stop backing up content. Second, users can keep the 20GB storage limit by tapping Settings and then iCloud. Head to Account, tap the current storage plan, and follow the prompts after choosing Downgrade Options. Apple provides a webpage covering iCloud's storage methods in greater depth.

Apple claims that 5GB of storage is enough, as iCloud is not a permanent storage location, unlike competitors such as Dropbox; Apple also said that the 5GB limit is rarely reached. Instead, users update and download data via iCloud. For users whose needs exceed 5GB of storage, Apple offers greater storage for a price, from 10GB for $20/year or $100/year for 100GB.

Mobilenapps.com compared iCloud, SkyDrive, and other cloud storage competitors. iCloud is different than the competition because it is not designed to store content over the long-term. Dropbox allows users to upload files and create folders while Google Docs stores content created through the service online.

Apple unveiled iCloud June 6, 2011, releasing Oct. 6, 2011.