Security Assertion Markup Language (SAML) is an open standard that is used to securely exchange authentication and authorization data between an organization-specific identity provider and a service provider (in this case, your ArcGIS Enterprise organization). This approach is known as SAML Web Single Sign On.
The organization is compliant with SAML 2.0 and integrates with identity providers that support SAML 2 Web Single Sign On. The advantage of setting up SAML is that you do not need to create additional logins for users to access your organization; instead, they use the login that is already set up in an identity store. This process is described throughout the documentation as setting up organization-specific logins.
For more information about configuring SAML with your organization, see Configure a SAML-compliant identity provider with a portal.