Microsoft Security, Compliance, and Identity Fundamentals SC-900 Practice Question

Identity federation creates a trust relationship between an identity provider-such as Azure Active Directory-and one or more service providers. When the trust is in place, the service provider accepts a security token issued by the identity provider and grants the user access without maintaining its own user store. This allows single sign-on across organizational boundaries while keeping authentication centralized. Directory synchronization only copies account data and still requires local authentication, authorization defines what a user can do after access is granted, and role-based access control is a method of assigning permissions, not of sharing identities between organizations. Therefore, federation is the required concept.