title: Name and Unnamed Semaphore
body: <p>I'm trying to understand the similarities and differences between named and unnamed semaphore so my google searches yielded me <a href="http://docs.oracle.com/cd/E19253-01/816-5137/sync-39/index.html" rel="noreferrer">this</a>. I had a question about the wording on the page though, it says:</p>
  
  <ul>
  <li>Unnamed semaphores might be <strong>usable</strong> by more than one process</li>
  <li>Named semaphores are <strong>sharable</strong> by several processes</li>
  </ul>
  
  <p>Do those two words create any important distinction between those two types of semaphores or are they irrelevant?</p>
  
  <p>So so far here's what I have:</p>
  
  <pre><code>Similarities
      -Several processes can do something with the semaphore
  
  Difference
      -Named are referenced with pathname and unnamed are referenced by pshared value
  </code></pre>
  
  <p>That's all I could glean from that definition. Is that everything and are they correct? Or am I missing some significant concept?</p>