Two-factor authentication, or 2FA, is a security step that asks for a second proof of identity on top of your password. Even if someone learns your password, they still cannot log in without that second factor, which is usually a short code that changes every few seconds.
There are a few common forms. SMS 2FA sends a code by text message, which is easy but can be vulnerable if an attacker hijacks your phone number. App-based 2FA, using an authenticator app on your device, is generally considered safer because it does not rely on your phone carrier. Some people use a physical security key for the strongest protection.
On crypto exchanges and accounts, enabling 2FA is one of the simplest and most effective protections available. Setting up an authenticator app rather than relying on SMS is a small step that meaningfully reduces the risk of account takeover.