An iPhone can be backed up to iCloud by turning on the iCloud Backup setting in the Settings menu of the device. Once the service is turned on, backups occur automatically whenever the device is plugged in, locked and connected to Wi-Fi.
To backup an iPhone to iCloud for the first time, ensure the device is running the latest version of iOS. To do this, navigate to the Settings menu, tap General, and tap Software Update to see if there are any updates available. If the device is running the latest version of iOS, navigate to the Settings menu, tap iCloud, and enter the Apple ID used on the device. This will create an iCloud account and activate the service.
To backup an iPhone for the first time, tap iCloud Backup in the iCloud menu, and tap Back Up Now. To activate automatic backups when the device is plugged in, locked and connected to Wi-Fi, slide the button beside iCloud Backup to the On position. If automatic backups are activated, iCloud backs up a host of information including device settings, app data, app organization and text messages. The iCloud comes with five gigabytes of free storage that can be upgraded to a maximum of one terabyte.