diff --git a/courses/databases_nosql/intro.md b/courses/databases_nosql/intro.md
index 9989365..2a3ba3d 100644
--- a/courses/databases_nosql/intro.md
+++ b/courses/databases_nosql/intro.md
@@ -1,22 +1,17 @@
-# DATABASES - NoSQL
+# NoSQL Concepts
 
 
-## Target Audience
-
-This Module is meant to be an introduction to NoSQL Databases. We will be touching upon the key concepts and trade offs in a distributed data system.
-
-
-## What to expect from this training
+## What to expect from this course
 
 At the end of training, you will have an understanding of what a NoSQL database is, what kind of advantages or disadvantages it has over traditional RDBMS, learn about different types of NoSQL databases and understand some of the underlying concepts & trade offs w.r.t to NoSQL.
 
 
-## What is not covered under this training
+## What is not covered under this course
 
 We will not be deep diving into any specific NoSQL Database. 
 
 
-## Agenda
+## Table of Contents
 
 
 
@@ -219,4 +214,4 @@ The table below summarizes the main differences between SQL and NoSQL databases.
 
 *   Developer productivity
 
-    NoSQL systems tend to map data based on the programming data structures. As a result developers need to perform fewer data transformations leading to increased productivity & fewer bugs.
\ No newline at end of file
+    NoSQL systems tend to map data based on the programming data structures. As a result developers need to perform fewer data transformations leading to increased productivity & fewer bugs.
diff --git a/courses/index.md b/courses/index.md
index 28d24aa..7db39ac 100644
--- a/courses/index.md
+++ b/courses/index.md
@@ -1,5 +1,5 @@
 # School of SRE
-![School of SRE](img/sos.png)
+![School of SRE](img/sos.png|width=100)
 Early 2019, we started visiting campuses to recruit the brightest minds to ensure LinkedIn and all the services that it is composed of is always available for everyone. This function at Linkedin falls in the purview of the Site Reliability Engineering team and Site Reliability Engineers ( SRE ) who are Software Engineers who specialize in reliability. SREs apply the principles of computer science and engineering to the design and development of computer systems: generally, large distributed ones.  
 
 As we continued on this journey we started getting a lot of questions from these campuses on what exactly site engineering roll entails? and, how could someone learn the skills and the disciplines involved to become a successful site engineer?   Fast forward a few months, and a few of these campus students had joined LinkedIn either as Interns or as full time engineers to become a part of the Site Engineering team, we also had a few lateral hires who joined our organization who were not from a traditional SRE background.  That's when a few of us got together and started to think about how we can on board new new graduate engineers to the site engineering team.
diff --git a/mkdocs.yml b/mkdocs.yml
index 39f0927..5187e45 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -12,6 +12,7 @@ nav:
         - Introduction: linux_basics/intro.md
         - Command Line Basics: linux_basics/command_line_basics.md
         - Server Administration: linux_basics/linux_server_administration.md
+        - Conclusion: linux_basics/conclusion.md
     - Git:
         - Git Basics: git/git-basics.md
         - Working With Branches: git/branches.md
@@ -33,11 +34,12 @@ nav:
 - Data:
     - Big Data:
         - Introduction: big_data/intro.md
-        - Overview of Big Data: big_data/overview.md
-        - Usage of Big Data techniques: big_data/usage.md
-        - Evolution of Hadoop: big_data/evolution.md
-        - Architecture of Hadoop: big_data/architecture.md
+        - Evolution and Architecure of Hadoop: big_data/evolution.md
         - Tasks and conclusion: big_data/tasks.md
+    - NoSQL Concepts:
+        - Introduction: databases_nosql/intro.md
+        - Key Concepts: databases_nosql/key_concepts.md
+        - References:  databases_nosql/further_reading.md
 - Systems Design:
     - Introduction: systems_design/intro.md
     - Scalability: systems_design/scalability.md
@@ -50,4 +52,5 @@ nav:
     - Network Security: security/network_security.md
     - Threat, Attacks & Defences: security/threats_attacks_defences.md
     - Writing Secure code: security/writing_secure_code.md  
+    - Conclusion: security/conclusion.md
 - Contribute: CONTRIBUTING.md