How does backup work?

I've never had to reset an iphone so I don't know what happens when you do.

I'm looking at the screen - AppleID : iCloud on a fully updated iPhone 12.

Assuming I've got icloud enabled for every app in the list and I've got icloud backup turned on, after a reset and logging in will my phone magically be right back to where I left it? Will all the installed apps, settings, logins, saved data (health, sms, call logs, location records etc), photos etc be ready to go as if I simply restarted the phone?

What happens if I turn icloud off for all of my apps? Will all of the local data and settings be saved in the iCloud backup file? And will a restore work the same as if I had iCloud turned on?

Thank you!