Here we will learn how to create a server instance in node.js. First of all we will have to check if the node.js is properly setup in our local machine. Let us create a file with name demo.js and write the below code in the file:

console.log(Testing the nodejs setup);

Now the code on the terminal we can see will be something like written below:

username@machinename:~$ cd path of the file
username@machinename:path of the file$ node demo.js

if the setup is installed properly you will see the output: Testing the nodejs setup.

Now to create the instance of the server we will do the following few steps as mentioned bellow:

1- We will load http module using the require directive as below:

var http = require(http);

this http variable is used to store the output returned by the module.

2- In the next step we will create an http instance that will have a call back function with request and response parameters.

http.createServer(function(req,resp){
	resp.writeHead(200,{'Content-Type':'text/plan'});
	resp.end("Hello World Today is Sunny day..!!");
}).listen(8081);
console.log('Server is listening on port 8081');

In the above code we have used the createServer function to create the server instance and use a listen method that will listen all the requests at the port 8081 from the client. If we write the code in the 1 and 2 step in a demo.js file and run the below command on the terminal

username@machinename:~$ cd path of the file
username@machinename:path of the file$ node demo.js

we will see the following output:

on the browser: Hello World Today is Sunny day..!!

on the terminal: Server is listening on port 8081