Before updating my iPhone 6 to iOS 10 via iTunes, I manually saved a backup of 9.3.5 to iTunes on my MBP. When iOS 10 installed, the installation process also seemed to create a backup before starting the installation process. When I go into iTunes to check my backups, I only see one backup from the day I installed iOS 10, so it appears that the installation process overwrote my earlier backup. Does the backup when done from iTunes back up the prior OS version or does it simply back up apps, data and settings? Can I assume that the one backup shown in iTunes is the 9.3.5 installation? Can I simply restore from this backup to get 9.3.5 back or do I need to download the iOS 9.3.5 version from Apple, assuming it's still available, and then restore from iTunes to get my apps, data and settings back? I've never reverted to an earlier Apple OS before, but iOS 10 is causing problems on my iPhone 6.