Google Account Verification is a simple, but effective method of security. It requires that when you set up a new device, you have to enter your Google account and verify that you’re the owner of that account by clicking through a link in an email.
What most people don’t realize is that by default when you set up your Android device with a Google account, the Factory Reset Protection feature is enabled by default.
It prevents someone from accessing the device (and therefore any data on the device) after a factory data reset unless the user knows the last Google username and password that was used to set up the device.
So, if you lose your phone or it’s stolen, the person who ends up with it can’t access the device unless they have your login credentials.