Explanation:
Box 1: Pass-through authentication.
This method allows users to authenticate using their on-premises passwords without syncing the password hashes to Microsoft Entra ID1.
Box 2: Single sign-on (SSO).
This feature allows users to sign in once and gain access to all their applications without needing to re-enter their credentials2.
https://learn.microsoft.com/en-us/entra/identity/hybrid/connect/how-to-connect-pta
https://learn.microsoft.com/en-us/entra/identity/hybrid/connect/choose-ad-authn