title: When does nodeJS check for the callback queue for executing callbacks?
body: <p>As I understand , a Node JS server continues to listen on a port for any incoming requests which means the thread is continuously busy ? When does it break from this continuous never ending loop and check if there are any events to be processed from the call back queue?</p>
  
  <p>2) When Node JS starts executing code of callback functions, the server is essentially stopped? It is not listening for further requests? I mean since only single thread is going to do both the task only one can be done at a time?</p>
  
  <p>Is this understanding correct or there's more to it?  </p>