Node.js - A Simple example for starting up

I have been trying to understand what is this Node.js, Got confused, and went through the Google to find the simple working of it, Finally I got a wonderful example in the following Link.

http://dailyjs.com/2012/05/03/windows-and-node-1/

It is Awesome, Some codes are Depticated, you can use teh following code to avoid warning.

var express = require('express');

var app = express();