Third-party authentication uses a trusted, external identity provider to validate user credentials before granting access to one or more IT systems. The authentication process returns identifying information, such as a username and group membership, that is used to authorize or deny the requested access.
Third-party authentication is available using the OpenID Connect, SAML 2.0, WS-Federation, and WS-Trust protocols. By using it, you can take advantage of advanced authentication requirements, like the use of smartcards or Multi-Factor Authentication (MFA), to increase confidence in the user's identity.
For more information, see What is third-party authentication?.