Fix Adding a zone documentation (#472)

Author: nvazquez

source/installguide/configuration.rst

@@ -264,7 +264,13 @@ and secondary storage.
 
 #. Click Add Zone. The zone creation wizard will appear.
 
-#. Choose one of the following network types:
+#. Choose one of the following zone types:
+
+   - **Core.** Core Zones are intended for Datacenter based deployments and allow the full range of Networking and other functionality in Apache CloudStack. Core zones have a number of prerequisites and rely on the presence of shared storage and helper Instances. For more information see :ref:`core-zone`.
+
+   - **Edge.** Edge Zones are lightweight zones, designed for deploying in edge computing scenarios. They are limited in functionality but have far fewer prerequisites than core zones. Please refer to :ref:`edge-zone`.
+
+#. If Core Zone is selected, choose one of the following network types:
 
    -  **Basic.** For AWS-style networking. Provides a single network
       where each instance is assigned an IP directly from the
@@ -526,6 +532,8 @@ Advanced Zone Configuration
 
 For Advanced zone, you may chose to select Edge which will allow creating an Edge Zone. If Edge is not selected then wizard will continue creating a Core zone.
 
+.. _core-zone:
+
 Core Zone
 *********
 
@@ -776,6 +784,8 @@ Core Zone
 #. Click Launch.
 
 
+.. _edge-zone:
+
 Edge Zone
 *********