What is two-factor authentication (2FA)?

Two-factor authentication (2FA) is a security process that requires users to present two different forms of identification before they can access an account or system. This method enhances security by requiring two separate components: something the user knows (like a password) and something the user has (like a smartphone, security token, or smart card). By combining these two factors, 2FA significantly reduces the risk of unauthorized access compared to relying solely on a password.

The other options do not accurately describe 2FA. The process that requires just a password is a single-factor authentication method, which lacks the added layer of security. A single form of identification also pertains to one-factor authentication, which does not provide sufficient protection against potential threats. Lastly, while physical security measures can protect hardware, they do not specifically define the concept of two-factor authentication, which focuses on user verification methods rather than physical equipment.