title: What does Exclusive in XOR really mean?
body: <p>Maybe this is just obvious to everyone but can someone explain where XOR (or Exclusive-OR) got its name from? What does the word <strong><em>Exclusive</em></strong> really mean? Not that it matters, but its just stuck in my head since morning.</p>
  
  <pre><code>OR:
  0 0 0
  0 1 1
  1 0 1
  1 1 1
  
  XOR:
  0 0 0
  0 1 1
  1 0 1
  1 1 0
  </code></pre>
  
  <p>Is it "exclusively 0 for inputs 1,1", "special version of OR" or something else?</p>