title: What is the difference between afferent couplings and efferent couplings of a class?
body: <p>Code quality metric tool like <a href="http://www.sonarsource.org/" rel="noreferrer">Sonar</a> does provide the ability to drill down to a class and find out the number of:</p>
  
  <ol>
  <li><em>Afferent (incoming) couplings</em></li>
  <li><em>Efferent (outgoing) couplings</em></li>
  </ol>
  
  <p>What are these two parameters? Can you please describe with a simple contrived example?</p>