title: Difference between NavigableSet, SortedSet and TreeSet in Java
body: <ul>
  <li>A <code>TreeSet</code> puts an element in <em>natural ordering</em> or by the provided
  <em>comparator</em>.</li>
  <li>A <code>SortedSet</code> is also keeps the element in <em>natural order</em></li>
  </ul>
  
  <p>But what is the difference between them and <code>NavigableSet?</code><br>
  Where are <code>NavigableSets</code> useful?</p>
  
  <p>Some example to show its usage would be nice for beginners.</p>