title: What is ref in Erlang?
body: <p>Going through this <a href="http://learnyousomeerlang.com/errors-and-processes#naming-processes" rel="nofollow noreferrer">link</a></p>
  
  <p>To identify a process,we would be using a Pid. When should a ref be used?</p>
  
  <p>I see this often while message sending/receiving but unable to interpret what role it plays in message interaction.</p>