iCloud backs up and stores all data on your iPhone/iPad/iPod in the cloud and offers up to 1 TB of storage (your first 5GB are free). To make a backup of your device using iCloud, you do not need to plug your device into a computer. Actually, it lets you make and use backups from anywhere with Wi-Fi.
Before getting started, please turn on iCloud Backup on your device.
After you’ve turned on iCloud Backup on your device, iCloud will automatically back up your device each day when:
That is it. To check whether a successful backup is created, you can tap Settings > iCloud > Storage > Manage Storage, and then select your device. You will see the latest backup file with time and size.