HTTP Basic Authentication: Used when a native API enforces basic authentication. Based on the modes selected, either uses configured basic authentication credentials to invoke a native service or it uses credentials from the authorization header of the incoming request to access the native API.

NTLM Authentication: Used when a native API enforces NTLM authentication. Based on the modes selected, either uses configured authentication credentials to obtain the NTLM token to invoke the native service or it uses credentials from the authorization header of the incoming request to obtain the NTLM token to access the native API.

OAuth2 Authentication: Used when a native API enforces OAuth authorization. Based on the modes selected, either uses configured OAauth token to invoke the native service or it uses the OAauth token of the incoming request to access native API.

Kerberos Authentication: Used when a service provider wants a web service client that does not have the ability to generate the Kerberos token to access a service enforced with the Kerberos policy. It is also used when service provider wants a web service client to access a service enforced with the Kerberos policy.

SAML Authentication: Used when a native API enforces SAML authentication. Based on the modes selected, either uses the WSS Username mode or the Kerberos Over Transport mode to get the SAML assertion token and access the native API.