Connect an iPhone to iCloud, Apples cloud storage service, by navigating to the iCloud section of the Settings app and following the on-screen instructions to associate your Apple ID with an iCloud account. You may also download other apps through the App Store to store data such as pictures, music or documents through the cloud.
Cloud storage refers to a type of data saving process wherein you are able to use a specific piece of software to store the information on a remote server, rather than locally on the device, and access it at any time over an Internet connection. All iPhones are able to access the Apple cloud storage service known as iCloud to save pictures, contacts, emails, notes and other data, as long as the device is able to run a version of the iOS operating system that supports the feature. After you create an iCloud account, you may designate the items you with to back up to the service through the phone's Settings app.
When you download third party cloud storage apps, you typically need to create an account with the company in order to manage your data through its cloud servers. Each service features its own storage limits, file size thresholds and special features. Some apps allow you to upload any type of file from your device to its servers, while others only specialize in a particular type of file. Read the App Store description for each app to understand its uses and limitations.