2FA (Two-Factor Authentication)
Quick definition
A second login step — usually a code from an authenticator app — that blocks account takeovers.
2FA requires something you have (a code on your phone) on top of something you know (your password). Even if your password leaks, attackers can't get in without the second factor.
Use an authenticator app rather than SMS where possible — SIM-swap attacks can intercept text messages. Enabling 2FA before depositing anything is rule one of exchange security.