updated security authentication

Author: KingdomOfEnds

articles/digital-twins/security-authenticating-apis.md

@@ -7,12 +7,12 @@ manager: bertvanhoof
 ms.service: digital-twins
 services: digital-twins
 ms.topic: conceptual
-ms.date: 09/30/2019
+ms.date: 11/22/2019
 ---
 
 # Connect to and authenticate with APIs
 
-Azure Digital Twins uses Azure Active Directory (Azure AD) to authenticate users and protect applications. Azure AD supports authentication for a variety of modern architectures. All of them are based on the industry-standard protocols OAuth 2.0 or OpenID Connect. In addition, developers can use Azure AD to build  single-tenant and line-of-business (LOB) applications. Developers also can use Azure AD to develop multitenant applications.
+Azure Digital Twins uses Azure Active Directory (Azure AD) to authenticate users and protect applications. Azure AD supports authentication for a variety of modern architectures. All of them are based on the industry-standard protocols OAuth 2.0 or OpenID Connect. In addition, developers can use Azure AD to build  single-tenant and line-of-business (LOB) applications. Developers also can use Azure AD to develop [multitenant applications](how-to-multitenant-applications.md).
 
 For an overview of Azure AD, visit the [fundamentals page](https://docs.microsoft.com/azure/active-directory/fundamentals/) for step-by-step guides, concepts, and quickstarts.