Multi-factor authentication (MFA) requires users to provide two or more verification factors to gain access. Factors include something you know (password), something you have (phone, security token), and something you are (biometrics). MFA significantly reduces unauthorized access risk, even if passwords are compromised. Common methods include authenticator apps (Google Authenticator, Authy), SMS codes, hardware security keys (YubiKey), and biometric verification. MFA is considered essential security for all online accounts.
Cybersecurity