title: Difference between port number and process id?
body: <ul>
  <li>Process id(aka PID) uniquely identifies a process running on a computer.</li>
  <li>Port number uniquely identifies a process running on a computer in a network.</li>
  </ul>
  <p>Why can we not use PID instead of port number for connecting to a program (along with IP and protocol) running on a computer in a network?</p>
  <p>Can someone explain how exactly the port number and PID work?</p>