Multi-factor authentication (MFA)

Multi-factor authentication, or MFA, means proving your identity in more than one way when you sign in. Factors are something you know (password or PIN), something you have (phone or security key) and something you are (fingerprint or face). It is also called two-factor authentication (2FA) or 2-step verification. Even if your password is stolen, an attacker still needs the other factor. From weakest to strongest, common methods are: SMS or voice codes; authenticator app codes and push prompts with number matching; then security keys and passkeys, which resist phishing. Any MFA is much better than none. Never share codes or approve prompts you did not start.