Before you begin the update to the latest version of iOS, you need to take a backup of your device through iTunes in case anything goes wrong. Here is a step-by-step guide on how to backup your iPhone or iPad using iTunes.
Step 1: Download iTunes on your Mac or PC.
Step 2: After installing the program, open iTunes and click on your device’s icon.
Step 3: Click on “Backup Now”. (Make sure you select “My Computer” for backup storage.)
Step 4: If you are backing up sensitive data (for e.g., passwords and HomeKit data), then check ‘Encrypt local backup’.
Your iPhone or iPad has been successfully backed up to your computer.