What is Multi-Factor Authentication?

Learn what multi-factor authentication is and how it works.

Multi-factor authentication (MFA) is an authentication method in which a computer user is granted access only after successfully presenting two or more pieces of evidence (or factors) to an authentication mechanism: knowledge (something the user and only the user knows), possession (something the user and only the user has), and inherence (something the user and only the user is). (Source: Wikipedia).