Two Step Verification is an extra layer of security that ensures that only you can access your account, even if someone knows your password.
To enable Two Step Verification, go to your Account Settings and click Enable. Once you enable Two Step Verification, you'll be asked for a security code in addition to your password when you sign in on a new device or from an unfamiliar location.
If you lose your phone or otherwise can't get codes via text, voice call, or Google Authenticator, you can use backup codes to sign in.
If you lose access to your phone and your backup codes, you can recover access to your account.
You can also turn off Two Step Verification.
With Two Step Verification, you'll protect your account with something you know (your password) and something you have (your phone or a Security Key).