title: What does the `listen` directive actually listen for in nginx?
body: <p>The syntax of <code>listen</code> directive is known as the following.</p>
  
  <pre><code>server {
      listen ADDRESS:PORT;
  }
  </code></pre>
  
  <p>But what the ADDRESS and PORT mean here?
  ADDRESS of client IP address? or server IP address? or the requested IP address? So as the PORT part, who's port to listen for??</p>
  
  <p>Suppose I have a situation like this
  <a href="https://i.stack.imgur.com/cz0rs.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cz0rs.jpg" alt="enter image description here"></a></p>
  
  <p>Would the correct arguments of the <code>listen</code> directive be this or not ? </p>
  
  <pre><code>listen 46.137.123.236:80;
  </code></pre>
  
  <p>And, in which case should I specify an IP address instead of <code>*:80</code>?</p>