iCloud: Back up your iOS device to iCloud
iCloud automatically backs up your iOS device information daily over Wi-Fi when your device is turned on, locked, and connected to a power source.
Back up automatically
On your iOS device, go to Settings > iCloud > Storage & Backup, then turn on iCloud Backup.
Back up manually
On your iOS device, go to Settings > iCloud > Storage & Backup, then tap Back Up Now.
For information about messages that may appear while backing up, see the Apple Support article iCloud: Troubleshooting creating an iCloud backup.