Updated config section

Change-Id: I445f2b222a7be3a6153438600eeebe727846e645
diff --git a/configuration/config.rst b/configuration/config.rst
index 6d9c11e..2189179 100644
--- a/configuration/config.rst
+++ b/configuration/config.rst
@@ -1,10 +1,47 @@
 Overview
---------
-Network Slice Configuration
----------------------------
+========
 
-Device Group Configuration
---------------------------
+Reference helm chart
+--------------------
 
-UE Provisioning
----------------
+    - `SD-Core Helm Chart Repository <https://gerrit.opencord.org/admin/repos/sdcore-helm-charts>`_
+
+Configuration Methods
+---------------------
+SD-Core supports 2 ways to configure network functions and micro services.
+
+    - Helm Chart
+
+        - Each individual network function and microservice has its own helm chart.
+        - User needs to provide override values and deploy the network functions as per their need.
+
+    - REST Config Interface
+
+        - Basic static configuration is passed through helm chart
+        - Dynamic slice creation APIs are provided through REST interface.
+        - REST APIs are defined to create/modify/delete network slice.
+        - REST APIs are also provided to provision subscribers and grouping the subscribers under device Group.
+
+Configuration
+-------------
+
+    - Network Slice Configuration
+
+        - Configuration to create a slice of network
+        - Slice contains the QoS configuration
+        - Group of devices assigned to network slice
+        - Site configuration including UPF, eNBs/gNB assigned to the slice
+
+    - Device Group Configuration
+
+        - Configuration of group of UEs
+        - QoS required for the device group
+        - IP domain configuration for the group of devices
+
+    - UE Provisioning
+
+        - Configuration of IMSI and its security keys configuration
+
+Sample Configuration
+--------------------
+