Active Directory Federation Services (ADFS) is a standards-based service and a feature of Windows Server that you can enable on a Windows Server machine. It provides an authentication provider for external users to log in to an on-premises environment over the internet.
ADFS offers the following features:
- Web SSO: This provides SSO for federated users when they access applications that are installed in the on-premises data center.
- Web Services (WS) - interoperability: Applications or users that don't use the Windows identity model but are compatible with the WS-Federation specification can still authenticate to the ADFS server and your on-premises applications.
- No external user account management:
