The SAML standard

The Security Assertion Markup Language (SAML), is an XML-based framework for communicating user authentication, entitlement, and attribute information.
As its name suggests, SAML allows business entities to make assertions regarding the identity, attributes, and entitlements of a subject (an entity that is often a human user) to other entities, such as a partner company or another enterprise application.

Using the built-in SAML support, users can authenticate with any of the supported authentication modules and be automatically logged into any service that supports SAML 2.0 or SAML 1.1 Single Sign-On methods.

Users already logged into a local Windows Active Directory environment can be automatically signed on to services supported by the SAML SSO service; no additional login will be required. External users can be prompted for other supported strong authentication methods such as one-time passwords.