Two-Factor Authentication (2FA)
A specific form of multi-factor authentication that combines exactly two verification methods to confirm identity.
Two-factor authentication↗ (2FA) is a specific, common form of multi-factor authentication that requires exactly two different types of proof to log in, almost always a password plus a second factor like a one-time code, an app notification, or a physical security key↗. It's the most widely deployed form of extra account protection across banking, email, and social media services.
Turning on 2FA is one of the highest-impact, lowest-effort security changes anyone can make, since it blocks the overwhelming majority of automated account-takeover attempts that rely purely on stolen or reused passwords. Authenticator apps and hardware security keys are generally considered more secure second factors than SMS text messages, which remain vulnerable to SIM-swapping and interception.