You can back up iPhone using iCloud or your computer. To decide which method is best for you, see > [your name] > iCloud.
The amount of iCloud storage used and the amount of iCloud storage available appear at the top of the screen.
You can view details about iCloud backups, such as the last backup, the next backup size, and the apps included in the backup.
Go to Settings use iTunes to back up iPhone.
At the top of the Finder window, click General.
Select “Back up all of the data on your iPhone to this Mac.”
To encrypt your backup data and protect it with a password, select “Encrypt local backup.”
Click Back Up Now.
Note: You can also connect iPhone to your computer wirelessly if you set up syncing over Wi-Fi.