Using iCloud on Your iPhone
iCloud, which isn’t an app and isn’t even physically on your devices when you enable it, lets you synchronize your Apple devices to share data and storage.
To use iCloud on your iPhone, first make sure that you are running the latest version of IOS – Apple’s operating system for mobile devices. To do this, go to the Settings menu from your Home screen and tap General. Then tap Software update. It will show you if there is an update available.
If you go from your Home screen to Settings and then tap iCloud, just tap Account to set up your Apple ID and password. Then set up your iCloud storage. You can get 5 GB free or you can upgrade to different levels of storage by paying various prices.
When you tap Done, it returns you to iCloud Setting. Tap Contacts and switch to On to share your contacts between devices you have set up on iCloud. There are separate screens here with options for photos, documents and data as well.
To check your storage, tap Settings, tap iCloud, tap Storage & Backup and then tap Manage Storage. Although iCloud is automatically backed up, you can perform manual backup simply be tapping Backup Now.
And here is some great news! If you lose your phone or your phone is stolen, you can go to Find My iPhone on the iPhone website and remotely lock or erase everything!