Multi-Factor Authentication - security method requiring two or more verification methods. Like needing both a key and fingerprint to open a safe.
Online banking uses MFA by requiring both your password and a text message code to log in.
All major clouds support MFA for human sign-in to the provider console and identity system. AWS uses IAM (and IAM Identity Center for SSO), Azure uses Microsoft Entra ID, Google uses Google Identity/Cloud Identity with Cloud IAM, and OCI uses OCI IAM. The core concept is the same: require an additional factor beyond a password, typically via an authenticator app, hardware key, or SMS (less recommended).