To start your application server, you just have to execute the following command, inside your application directory:
$ npm start
Alternatively, use the following command to start the server and keep it running even after your server session ends. Replace FILE with the correct filename for your application.
$ forever start FILE.js
If you are using a recent Express version (greater than 4.0), you should use the following command instead:
Port 3000 is the default port used by Express when creating the template. This means that you may receive an error similar to the below when starting the server:
Error: listen EADDRINUSE at errnoException (net.js:670:11) at Array.0 (net.js:771:26) at EventEmitter._tickCallback (node.js:190:38)
This means that the port is already in use. Edit the app.js script and change the line containing app.listen() to use a different port number, as below. Then, start the application again.