Multi-Factor Authentication (MFA) FAQs
Important things to know
You won't have to do the second step very often. Some people worry that multifactor authentication is going to be inconvenient, but generally it's only used the first time you sign into an app or device, or the first time you sign in after changing your password. After that you'll just need your primary factor, usually a password, like you do now.
The extra security comes from the fact that somebody trying to break into your account is probably not using your device, so they'll need to have that second factor to get in.