In additional settings >backup and restore> you will find different settings. For example in local backup you can encrypt your data on your device, you can also find in save my data: backup data on google servers.. The google account, to my opinion, is the one you use on any android device, so you don't need to specify it here becausr it's done since the first time you switched your telephone ON and entered your google address, all you have to do is to switch ON "backup dei miei dati" and go further.
This is a reply to riccardo ! ☺