title: socket.bind() vs socket.listen()
body: <p>I've learned how to write a python server, and figured out that I have a hole in my knowledge.
  Therefore, I would glad to know more about the differences between the commands <code>bind()</code>, <code>listen()</code> of the module called socket.</p>
  <p>In addition, when I use <code>bind()</code> with a specific port as a parameter, Is the particular port being in use already, before using the <code>listen()</code> method?!</p>