Express router allows you to create multiple "mini apps" so you can namespace your api, public, auth and other routes into separate routing systems.

var express   = require('express');
var app       = express();
var router    = express.Router();

router.get('/', function(req, res){
   res.send('Get request received');
});

router.post('/', function(req, res){
   res.send('Post requestreceived');
});

app.use('/', router);

app.listen(8080);

var express   = require('express');
var app       = express();
var router    = express.Router();

app.route('/user')
  .get(function (req, res) {
    res.send('Get a random user')
  })
  .post(function (req, res) {
    res.send('Add a user')
  })
  .put(function (req, res) {
    res.send('Update the user details')
  })
  .delete(function (req, res) {
    res.send('Delete a user')
  });