Docker file explanation

content/en/guides/contributorguide/Application build and containerisation/02_docker.md

@@ -9,39 +9,54 @@ description: >
 
 ### containerize react application
 
-**Before Starting** 
+**Before Starting**
 
  - I have wsl2 installed in my system and I am using my Linux environment to run this application. I also advised developers to use Linux environment as we will be going to use lot of command line stuff later.
 
-**Software needed :**  
-Node js   
-npm    
-VS Code   
-Linux in WSL2  
+**Software needed :**
+Node js
+npm
+VS Code
+Linux in WSL2
 
-**Fixing one error** 
+**Fixing one error**
 
 In the previous step, we run our application normally. Now its time to build its docker image. But after making image and running application, it is showing ENOENT error. So write this line in this file - `node_modules\react-dev-utils\openBrowser.js` at line 90.
 
     if (browser === undefined) {
-    return  false; 
+    return  false;
     }
 
 
 **Dockerfile**
 
 In the root of the folder create a file named as Dockerfile and copy the below content in it.
 ```
+# Choose the Docker image
 FROM  node:14-alpine  AS  development
+
+# Set your environment where your application will run
 ENV  NODE_ENV  development
+
+# Set you working directory for your application
 WORKDIR  /app
+
+# Copy the configuration files
 COPY  package.json  .
 COPY  yarn.lock  .
+
+# Install all the dependencies
 RUN  yarn  install
+
+# Copy all the files and folders in the current directory to the Docker container
 COPY  .  .
+
+# Expose the port
 EXPOSE  3000
+
+# Set your commands to start the application
 CMD  [  "yarn",  "start"  ]
-  ```  
+  ```
 
 **Build an image**
 
@@ -58,4 +73,3 @@ docker run -it -p 3000:3000 client
 It will take some time and this will be showing in your terminal, and your application is started now.
 Now go to `localhost:3000` and check your application running from inside a container.
 ![react Tab](/react_app.png)
-