nodejs - dependencies (very basic one) - express - > it is a part of nodejs or a plugin

i am very much interested to learn node.js and now.js . While trying to learn node.js , i found this one http://expressjs.com . Is this a part of node.js that i should learn or it is something like a plugin ? We can create server simply using this :

      var http = require('http');
      http.createServer(function (req, res) {
        res.writeHead(200, {'Content-Type': 'text/plain'});
        res.end('Hello World\n');
       }).listen(1337, '127.0.0.1');
      console.log('Server running at http://127.0.0.1:1337/');

Then y some people use that express ? what is the difference ? Thankyou.

Express is for web development, where Node.js is for anything server-side javascript.

You can look up the Express.js guide which will tell you way more: http://expressjs.com/guide.html

Express JS is again a sugar layer or utility module for Node JS to routing requests. its not part of node installable as of now. but apart from that it has few more features like, (as per the website) -

  • Robust routing Redirection helpers Dynamic view helpers Application
    level view options Content negotiation Application mounting Focus on
    high performance View rendering and partials support Environment
    based configuration Session based flash notifications Built on
    Connect Executable for generating applications quickly High test
    coverage

http://expressjs.com/