How does Multi-Factor Authentication work?

Do I have to do the second step every time I log in?

Does checking “Don’t ask again on this device” make me less secure?

Are there other options for my second step?

What if I don’t have my smartphone and cannot approve the MFA authentication?

What if I don’t have a mobile phone?

How can I change my MFA settings?

How can I receive the prompt on additional smartphones/tablets?

How do I add a phone number to my Google MFA?

Is any authentication method more secure?

What if I get a prompt or code but I am not signing in?

What if I get a new smartphone and/or change my phone number?

I still have questions.