Two-factor authentication (2FA) is a specific type of multi-factor authentication (MFA). While MFA refers broadly to using two or more credentials to verify users, 2FA specifically requires two layers - a password plus a second factor like a SMS code or authenticator app. So all 2FA setups qualify as forms of MFA, but not all MFA configurations are limited to just two factors. Some use three or even four factors for maximum security. Generally 2FA offers the best balance of enhanced security with reasonable user impact.