What are Active Directory Federation Services?

Active Directory Federation Services (ADFS) is a component of Microsoft Windows Server that provides Single Sign-On (SSO) access across organisational boundaries. It facilitates secure identity federation and authentication processes between different trusted entities, enabling users to access resources seamlessly across disparate systems or domains without needing separate credentials for each.

ADFS enables SSO capabilities by allowing users to authenticate once with their home organisation's identity provider (IdP) and gain access to resources in other trusted organisations or cloud services without re-entering credentials. This allows for secure exchange of authentication and authorisation information, maintaining user identities and attributes across organisational boundaries.

By integrating with Active Directory and IAM solutions, ADFS enforces access control policies based on user attributes, roles and group memberships. It supports fine-grained access control mechanisms, allowing organisations to grant appropriate permissions to users based on their identity and context. It can also be configured to support multi-factor authentication methods, adding an extra layer of security during the authentication process.