Added note on other ways to handle SSO

Author: JimVance

articles/active-directory/develop/single-sign-on-saml-protocol.md

@@ -25,6 +25,9 @@ The protocol diagram below describes the single sign-on sequence. The cloud serv
 
 ![Single Sign-On (SSO) Workflow](./media/single-sign-on-saml-protocol/active-directory-saml-single-sign-on-workflow.png)
 
+> [!NOTE]
+> This article discusses using SAML for single sign-on. For more information on other ways to handle single sign-on (for example, by using OpenID Connect or Integrated Windows Authentication), see [Single sign-on to applications in Azure Active Directory](../manage-apps/what-is-single-sign-on.md).
+
 ## AuthnRequest
 
 To request a user authentication, cloud services send an `AuthnRequest` element to Azure AD. A sample SAML 2.0 `AuthnRequest` could look like the following example: