title: What's the difference between call by reference and copy/restore
body: <p>What's the difference in the outcome between call by reference and copy/restore?</p>
  
  <p>Background: I'm currently studying distributed systems. Concerning the passing of reference parameters for remote procedure calls, the book states that: "the call by reference has been replaced by copy/restore. Although this is not always identical, it is good enough". I understand how call by reference and copy/restore work in principle, but I fail to see where a difference in the result may be?</p>