Two-Factor Authentication (2FA) is a type of MFA that specifically requires exactly two authentication factors to verify a user’s identity. It strengthens security by ensuring that even if one factor (such as a password) is compromised, an attacker still needs the second factor.
Examples of 2FA:
- Password + SMS Code
- PIN + Fingerprint Scan
- Password + One-Time Code from an Authenticator App (e.g., Google Authenticator)
2FA is a subset of MFA because it strictly requires two factors, whereas MFA can require two or more.