title: What does it mean to bind() a socket to any address other than localhost?
body: <p>I don't understand what it <em>means</em> to <code>bind</code> a socket to any address other than 127.0.0.1 (or ::1, etc.).<br>
  Am I not -- <em>by definition</em> -- binding the socket to a port on <strong>my own</strong> machine.. which is localhost?<br>
  What sense does it make to bind or listen to <em>another</em> machine or IP address's port?<br>
  Conceptually, it just doesn't make sense to me!</p>
  
  <p>(This has proven surprisingly hard to Google... possibly because I'm not Googling the right terms.)</p>