diff --git a/README.md b/README.md
index 9e0034c..3b8da8b 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,32 @@
-# DesignPatternsJava9
-This repo consists Gang of Four Design patterns code on Java 9. Each branch in the repository has code of 1 design pattern. Switch repository to try out different design patterns.
+# What is Command Design Pattern 
+Command encapsulate all information needed to perform an action. It allows the requester of a particular action to be decoupled from the object that performs the action.
+
+## Diagram
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/command-pattern/diagrams/Command%20Design%20Pattern%20class%20diagram.jpeg "Diagram")
+
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/command-pattern/diagrams/Command-Design-Pattern-general%20-%20Page%201.png "Diagram")
+
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/command-pattern/diagrams/command%20sequence%20diagram.png "Diagram")
+
+### When to use Command Design Pattern 
+The invoker should be decoupled from the object handling the invocation.
+
+### Learn Design Patterns with Java by Aseem Jain
+This repository contains working project code used in video Course by Packt Publication with title "Learn Design Patterns with Java " authored by "Aseem Jain".
+
+### Course link: 
+https://www.packtpub.com/application-development/learn-design-patterns-java-9-video
+
+### ![ http://in.linkedin.com/in/premaseem](https://github.com/premaseem/DesignPatternsJava9/blob/master/linkedin.png "http://in.linkedin.com/in/premaseem") Profile:  http://in.linkedin.com/in/premaseem
+
+### Authors blog on design patterns:
+https://premaseem.wordpress.com/category/computers/design-patterns/
+
+### Software Design pattern community face book page:
+https://www.facebook.com/DesignPatternGuru/
+
+### Note: 
+* This code base will work on Java 9 and above versions. 
+* `diagrams` folders carry UML diagrams.
+* `pattern` folder has code of primary example. 
+* `patternBonus` folder has code of secondary or bonus example.
diff --git a/diagrams/Command Design Pattern class diagram.jpeg b/diagrams/Command Design Pattern class diagram.jpeg
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diff --git a/diagrams/command sequence diagram.png b/diagrams/command sequence diagram.png
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diff --git a/pattern/src/com/premaseem/Client.java b/pattern/src/com/premaseem/Client.java
index 15f05df..2c38869 100644
--- a/pattern/src/com/premaseem/Client.java
+++ b/pattern/src/com/premaseem/Client.java
@@ -1,13 +1,55 @@
 package com.premaseem;
 
+import java.util.Scanner;
+
 /*
 @author: Aseem Jain
 @title: Design Patterns with Java 9
 @link: https://premaseem.wordpress.com/category/computers/design-patterns/
-@copyright: 2018 Packt Publication
 */
 public class Client {
     public static void main (String[] args) {
-        System.out.println("Singleton cook example ");
+        Scanner scanInput = new Scanner(System.in);
+        System.out.println("Light switch Project using COMMAND DESIGN PATTERN \n ");
+
+       /** After implementing Command design pattern **/
+
+       // All available Commands will be created and init by command factory
+       CommandFactory cf = CommandFactory.init();
+
+       // Will list all commands which can be executed
+       cf.listCommands();
+
+       // Commands can be added and listed dynamically with ZERO code changes in client side
+       System.out.println("Master - what command you want to execute ");
+       String command = scanInput.next();
+
+       // Actual execution of command will happen
+       cf.executeCommand(command);
+
+        /** Lessons Learnt - AFTER CODE
+         # New commands can be added dynamically with ease
+         # Client is loosely coupled and have no knowledge of encapsulated commands
+         # Zero code changed needed at client when new commands are added
+         */
+
+
+       /** BEFORE CODE
+        // Assume you will invoke a method to execute turn on method
+        if (command.equalsIgnoreCase("LightOn")){
+            System.out.println("Light turned on");
+        }
+        else if (command.equalsIgnoreCase("LightOff")){
+            System.out.println("Light turned off");
+        }
+        else {
+            System.out.println(command+ " Command not found");
+        }
+
+        // Lessons Learnt - BEFORE CODE
+        // Lots of if else ladder
+        // Commands cannot be added Dynamically
+        // Code is tightly coupled, no separation of responsibility
+        */
     }
 }
diff --git a/pattern/src/com/premaseem/Command.java b/pattern/src/com/premaseem/Command.java
new file mode 100644
index 0000000..038047c
--- /dev/null
+++ b/pattern/src/com/premaseem/Command.java
@@ -0,0 +1,14 @@
+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+/**
+ * The Command functional interface.
+ */
+@FunctionalInterface
+public interface Command {
+    public void execute();
+}
diff --git a/pattern/src/com/premaseem/CommandFactory.java b/pattern/src/com/premaseem/CommandFactory.java
new file mode 100644
index 0000000..e1e8572
--- /dev/null
+++ b/pattern/src/com/premaseem/CommandFactory.java
@@ -0,0 +1,47 @@
+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public final class CommandFactory {
+    private final Map<String, Command> commands;
+
+    private CommandFactory() {
+        commands = new HashMap<>();
+    }
+
+    public void addCommand(final String name, final Command command) {
+        commands.put(name, command);
+    }
+
+    public void executeCommand(String name) {
+        if (commands.containsKey(name)) {
+            commands.get(name).execute();
+        }else{
+            System.out.println(name+ " Command not found");
+        }
+    }
+
+    public void listCommands() {
+        System.out.println("Available commands: " + commands.keySet().stream().collect(Collectors.joining(", ")));
+    }
+
+    /* Factory pattern */
+    public static CommandFactory init() {
+        final CommandFactory cf = new CommandFactory();
+
+        // commands are added here using lambdas.
+        // It is also possible to dynamically add commands without editing the code.
+        cf.addCommand("LightOn", () -> System.out.println("Light turned on"));
+        cf.addCommand("LightOff", () -> System.out.println("Light turned off"));
+
+        return cf;
+    }
+}
diff --git a/patternBonus/src/com/premaseem/Client.java b/patternBonus/src/com/premaseem/Client.java
deleted file mode 100644
index 15f05df..0000000
--- a/patternBonus/src/com/premaseem/Client.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.premaseem;
-
-/*
-@author: Aseem Jain
-@title: Design Patterns with Java 9
-@link: https://premaseem.wordpress.com/category/computers/design-patterns/
-@copyright: 2018 Packt Publication
-*/
-public class Client {
-    public static void main (String[] args) {
-        System.out.println("Singleton cook example ");
-    }
-}
diff --git a/patternBonus/src/com/premaseem/commandPattern/ClientForRemoteControl.java b/patternBonus/src/com/premaseem/commandPattern/ClientForRemoteControl.java
new file mode 100644
index 0000000..c2195bd
--- /dev/null
+++ b/patternBonus/src/com/premaseem/commandPattern/ClientForRemoteControl.java
@@ -0,0 +1,41 @@
+package com.premaseem.commandPattern;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+
+import java.util.Scanner;
+
+public class ClientForRemoteControl {
+
+	public static void main(String[] args) {
+		Scanner scan = new Scanner(System.in);
+		int repeatRunFlag = 1;
+		RemoteControl remote = new RemoteControl();
+		RemoteControlLoader loader = new RemoteControlLoader(remote);
+		loader.load();
+		while (repeatRunFlag == 1) {
+
+			System.out.println("This is the Client Main Command Pattern with Home Automation system ");
+			
+			System.out.println("Loading the remote with approviate commands and mapping them in slots ... ");
+			
+			System.out.println("Please press the any command between 0 to 10 for operation ");
+			System.out.println("Remember 11 is for Master off, \n 0 is for UNDO and \n 10 is undomacro mode");
+
+
+			int remoteButtonNumber = scan.nextInt();
+			remote.remoteButtonPress(remoteButtonNumber);
+
+			System.out.println("\n $$$$$$$$$$$$$$$$$$$$  Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
+			System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
+			try {
+				repeatRunFlag = scan.nextInt();
+			} catch (Exception e) {
+				repeatRunFlag = 0;
+			}
+		}
+	}
+}
diff --git a/patternBonus/src/com/premaseem/commandPattern/Command.java b/patternBonus/src/com/premaseem/commandPattern/Command.java
new file mode 100644
index 0000000..6c092c3
--- /dev/null
+++ b/patternBonus/src/com/premaseem/commandPattern/Command.java
@@ -0,0 +1,236 @@
+package com.premaseem.commandPattern;
+
+import java.util.Arrays;
+import java.util.List;
+
+public interface Command {
+	public void execute ();
+	public void undo ();
+}
+
+
+class MasterOffcommand implements Command{
+	List<Command> commandMacro;
+	public MasterOffcommand(Command... commands){
+		commandMacro = Arrays.asList(commands);
+	}
+	
+	@Override
+    public void execute() {
+		for(Command cmd:   commandMacro ){
+		System.out.println("putting off  "+ cmd.getClass().getSimpleName() );
+			cmd.execute();
+		}
+		
+    }
+
+	@Override
+    public void undo() {
+	}
+}
+
+class UndocommandMacro implements Command{
+	RemoteControl remoteControl;
+	
+	public UndocommandMacro(RemoteControl Command){
+		this.remoteControl = Command;
+	}
+	
+	@Override
+    public void execute() {
+		for(Command cmd:   remoteControl.getCommandMacro() ){
+		System.out.println("Undoing "+ cmd.getClass().getSimpleName() );
+			cmd.undo();
+		}
+    }
+
+	@Override
+    public void undo() {
+		for(Command cmd:   remoteControl.getCommandMacro() )
+		cmd.undo();
+	}
+}
+
+class Undocommand implements Command{
+	Command Lastcommand;
+	RemoteControl remoteControl;
+	
+	public Undocommand(RemoteControl Command){
+		this.remoteControl = Command;
+	}
+	
+	@Override
+    public void execute() {
+		System.out.println(remoteControl.getLastCommand());
+		remoteControl.getLastCommand().undo();
+    }
+
+	@Override
+    public void undo() {
+		remoteControl.getLastCommand().undo();
+	}
+}
+
+
+class LightON implements Command{
+	Light light;
+	public LightON(Light light){
+		this.light = light;
+	}
+	@Override
+    public void execute() {
+	    light.turnON();
+    }
+
+	@Override
+    public void undo() {
+	    light.turnOFF();
+    }
+}
+
+class LightOFF implements Command{
+	Light light;
+	public LightOFF(Light light){
+		this.light = light;
+	}
+	@Override
+    public void execute() {
+	    light.turnOFF();
+    }
+
+	@Override
+    public void undo() {
+	    light.turnON();
+    }
+}
+
+class FanOFF implements Command{
+	Fan device;
+	public FanOFF(Fan device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.turnOFF();
+    }
+
+	@Override
+    public void undo() {
+	    device.turnHIGH();
+    }
+}
+
+class FanLOW implements Command{
+	Fan device;
+	public FanLOW(Fan device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.turnLOW();
+    }
+
+	@Override
+    public void undo() {
+	    device.turnHIGH();
+    }
+}
+
+class FanMEDIUM implements Command{
+	Fan device;
+	public FanMEDIUM(Fan device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.turnMED();
+    }
+
+	@Override
+    public void undo() {
+	    device.turnHIGH();
+    }
+}
+
+class FanHIGH implements Command{
+	Fan device;
+	public FanHIGH(Fan device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.turnHIGH();
+    }
+
+	@Override
+    public void undo() {
+	    device.turnOFF();
+    }
+}
+
+
+class TVON implements Command{
+	TV device;
+	public TVON(TV device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.turnON();
+    }
+
+	@Override
+    public void undo() {
+	    device.turnOFF();
+    }
+}
+
+class TVOFF implements Command{
+	TV device;
+	public TVOFF(TV device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.turnOFF();
+    }
+
+	@Override
+    public void undo() {
+	    device.turnON();
+    }
+}
+
+class TVChannelUP implements Command{
+	TV device;
+	public TVChannelUP(TV device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.channelUP();;
+    }
+
+	@Override
+    public void undo() {
+	    device.channelDOWN();
+    }
+}
+
+class TVChannelDOWN implements Command{
+	TV device;
+	public TVChannelDOWN(TV device){
+		this.device = device;
+	}
+	@Override
+    public void execute() {
+	    device.channelDOWN();
+    }
+
+	@Override
+    public void undo() {
+	    device.channelUP();
+    }
+}
+
+
diff --git a/patternBonus/src/com/premaseem/commandPattern/Device.java b/patternBonus/src/com/premaseem/commandPattern/Device.java
new file mode 100644
index 0000000..d7274f2
--- /dev/null
+++ b/patternBonus/src/com/premaseem/commandPattern/Device.java
@@ -0,0 +1,83 @@
+package com.premaseem.commandPattern;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+public interface Device {
+    void turnOFF();
+}
+
+
+// There are several 3rd component or devices. They would ack as reciever of the command. Each command object would wrap them.
+class Light implements Device {
+    void turnON() {
+        System.out.println("Turn ON Light");
+    }
+
+    public void turnOFF() {
+        System.out.println("Turn OFF Light");
+    }
+}
+
+class Fan implements Device {
+
+    public enum speed{
+        OFF,LOW,MED,HIGH
+    }
+    speed fanSpeed;
+
+    public void turnOFF() {
+        fanSpeed = speed.OFF;
+        System.out.println("Turn OFF FAN");
+    }
+    void turnLOW() {
+        fanSpeed = speed.LOW;
+        System.out.println("Turn OFF FAN");
+    }
+    void turnMED() {
+        fanSpeed = speed.MED;
+        System.out.println("Turn OFF FAN");
+    }
+    void turnHIGH() {
+        fanSpeed = speed.HIGH;
+        System.out.println("Turn OFF FAN");
+    }
+
+}
+
+class TV implements Device {
+    void turnON() {
+        System.out.println("Turn ON TV");
+    }
+
+    public void turnOFF () {
+        System.out.println("Turn OFF TV");
+    }
+    void channelUP() {
+        System.out.println("Channel UP TV");
+    }
+
+    void channelDOWN() {
+        System.out.println("Channel Down TV");
+    }
+
+}
+
+class MusicSystem implements Device {
+    void turnON() {
+        System.out.println("Turn ON Music System");
+    }
+
+    public void turnOFF () {
+        System.out.println("Turn OFF Music System");
+    }
+    void volumeUP() {
+        System.out.println("Volume up Music System");
+    }
+
+    void volumeDOWN() {
+        System.out.println("Volume down Music System");
+    }
+}
diff --git a/patternBonus/src/com/premaseem/commandPattern/RemoteControl.java b/patternBonus/src/com/premaseem/commandPattern/RemoteControl.java
new file mode 100644
index 0000000..7a888ea
--- /dev/null
+++ b/patternBonus/src/com/premaseem/commandPattern/RemoteControl.java
@@ -0,0 +1,35 @@
+package com.premaseem.commandPattern;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class RemoteControl {
+
+	List<Command> slots = new ArrayList<Command>(15);
+	Command lastCommand;
+	List<Command> commandMacro = new ArrayList<Command>(3);
+	
+	public List<Command> getCommandMacro() {
+		return commandMacro;
+	}
+
+	public Command getLastCommand() {
+		return lastCommand;
+	}
+
+	public void setLastCommand(Command lastCommand) {
+		this.lastCommand = lastCommand;
+	}
+
+	public void setCommandOnSlot( int i,Command cmd) {
+		slots.add(i, cmd);
+    }
+
+	public void remoteButtonPress(int keyNumber){
+		Command command = slots.get(keyNumber);
+		command.execute();
+		setLastCommand(command);
+		commandMacro.add(command);
+	}
+}
+
diff --git a/patternBonus/src/com/premaseem/commandPattern/RemoteControlLoader.java b/patternBonus/src/com/premaseem/commandPattern/RemoteControlLoader.java
new file mode 100644
index 0000000..d242748
--- /dev/null
+++ b/patternBonus/src/com/premaseem/commandPattern/RemoteControlLoader.java
@@ -0,0 +1,37 @@
+package com.premaseem.commandPattern;
+
+public class RemoteControlLoader {
+
+	RemoteControl remote;
+
+	public RemoteControlLoader(RemoteControl remote) {
+		this.remote = remote;
+	}
+
+	public void load() {
+		// Create instance of 3rd party devices
+		Light light = new Light();
+		Fan fan = new Fan();
+		TV tv = new TV();
+		
+//		Command cmd =  new LightON(light);
+		remote.setCommandOnSlot(0,new Undocommand(remote));	
+		remote.setCommandOnSlot(1,new LightON(light));
+		LightOFF lightOff = new LightOFF(light);
+		remote.setCommandOnSlot(2,lightOff);
+		FanOFF fanOff = new FanOFF(fan);
+		remote.setCommandOnSlot(3,fanOff);
+		remote.setCommandOnSlot(4,new FanLOW(fan));
+		remote.setCommandOnSlot(5,new FanMEDIUM(fan));
+		remote.setCommandOnSlot(6,new FanHIGH(fan));
+		remote.setCommandOnSlot(7,new TVON(tv));
+		TVOFF tvOff = new TVOFF(tv);
+		remote.setCommandOnSlot(8,tvOff);
+		remote.setCommandOnSlot(9,new TVChannelUP(tv));
+		remote.setCommandOnSlot(10,new UndocommandMacro(remote));
+		remote.setCommandOnSlot(11,new MasterOffcommand(lightOff,fanOff,tvOff));
+		
+
+	}
+}
+