Update api-management-howto-integrate-internal-vnet-appgateway.md

Acrolinx changes

Author: simonkurtz-MSFT

articles/api-management/api-management-howto-integrate-internal-vnet-appgateway.md

@@ -50,7 +50,7 @@ To follow the steps described in this article, you must have:
 
 ## Scenario
 
-In this article, you learn how to use a single API Management instance for internal and external consumers and make it act as a single front end for both on-premises and cloud APIs. You create an API Management instance of the newer single-tenant version 2 (stv2) type. You also understand how to expose only a subset of your APIs for external consumption by using routing functionality available in Application Gateway. In the example, the APIs are highlighted in green.
+In this article, you learn how to use a single API Management instance for internal and external consumers and make it act as a single front end for both on-premises and cloud APIs. You create an API Management instance of the newer single-tenant version 2 (stv2) type. You learn how to use public (external) and private (internal) listeners in Application Gateway and you how to expose only a subset of your APIs for external consumption by using routing functionality available in Application Gateway. In the example, the APIs are highlighted in green.
 
 In the first setup example, all your APIs are managed only from within your virtual network. Internal consumers can access all your internal and external APIs. Traffic never goes out to the internet. High-performance connectivity can be delivered via Azure ExpressRoute circuits. In the example, the internal consumers are highlighted in orange.
 
@@ -64,7 +64,7 @@ In the first setup example, all your APIs are managed only from within your virt
 * **Listener**: The listener has a front-end port, a protocol (Http or Https, these values are case sensitive), and the Transport Layer Security (TLS) certificate name (if configuring TLS offload).
 * **Rule**: The rule binds a listener to a back-end server pool.
 * **Custom health probe**: Application Gateway, by default, uses IP address-based probes to figure out which servers in `BackendAddressPool` are active. API Management only responds to requests with the correct host header, so the default probes fail. You define a custom health probe to help the application gateway determine that the service is alive and should forward requests.
-* **Custom domain certificates**: To access API Management from the internet, create DNS records to map its host names to the Application Gateway front-end IP address. This mapping ensures that the Host header and certificate sent to API Management are valid. In this example, we use three certificates. They're for API Management's gateway (the back end), the developer portal, and the management endpoint.
+* **Custom domain certificates**: To access API Management from the internet, create Domain Name System (DNS) records to map its host names to the Application Gateway front-end IP address. This mapping ensures that the Host header and certificate sent to API Management are valid. In this example, we use three certificates. They're for API Management's gateway (the back end), the developer portal, and the management endpoint.
 
 ### Expose the developer portal and management endpoint externally through Application Gateway
 
@@ -546,7 +546,7 @@ API Management configured in a virtual network provides a single gateway interfa
 
 ## Next steps
 
-* Set up using an [Azure Resource Manager template](https://github.com/Azure/azure-quickstart-templates/tree/master/quickstarts/microsoft.apimanagement/api-management-create-with-internal-vnet-application-gateway).
+* Set up using an [Azure Resource Manager template](https://github.com/Azure/azure-quickstart-templates/tree/master/quickstarts/microsoft.apimanagement/api-management-create-with-internal-vnet-application-gateway)
   
 * Learn more about Application Gateway: