Which authentication method employs multiple verification factors for increased security?

Multi-Factor Authentication (MFA) enhances security by requiring users to provide multiple forms of verification before granting access to a system. This method typically involves combining something the user knows (like a password), something the user has (such as a smartphone or a hardware token), and sometimes something the user is (like biometrics or facial recognition). This layered approach ensures that even if one factor is compromised, unauthorized access is still unlikely.

In comparison to Single Sign-On, which streamlines the authentication process by allowing users to log in once to access multiple systems, MFA focuses on strengthening security through multiple verification methods. Similarly, while a username and password are fundamental forms of authentication, they typically represent a single-factor approach, making them less secure when used alone. Two-Step Verification, while similar, usually consists of just two factors (often a password plus a code sent to a phone), which is a subset of what MFA can encompass. MFA can include various combinations and additional factors beyond just two, thus providing a more comprehensive security framework.