Two-factor authentication (TFA, T-FA or 2FA) is an approach to authentication which requires the presentation of “two or more” of the three authentication “factors”.
Two-factor authentication is often confused with other forms of authentication. Two factor authentication requires the use of two of the three regulatory-approved authentication factors. These factors are:
Something the user knows (e.g., password, PIN);
Something the user has (e.g., ATM card, smart card); and
Something the user is (e.g., biometric characteristic, such as a fingerprint).