What is multi-factor authentication (MFA)?

Multi-factor authentication (MFA) is a security process that enhances access control by requiring users to provide multiple forms of verification before granting them access to a resource. This typically involves combining something the user knows (such as a password), something the user has (like a smartphone or a security token), and possibly something the user is (biometric factors such as fingerprints or facial recognition).

The primary advantage of MFA is that it significantly increases the security of user accounts and sensitive information. If one factor, like a password, is compromised, attackers would still need additional verification methods to gain access, effectively reducing the risk of unauthorized access.

In contrast, relying solely on a single verification method, as suggested in the other choices, does not provide this extra layer of security. Options that mention requiring only a password or a single verification method fail to capture the multi-dimensionality that characterizes MFA. Therefore, the process of using multiple verification methods is what distinctly defines and strengthens the concept of multi-factor authentication.