title: In UML class diagrams, what are Boundary Classes, Control Classes, and Entity Classes?
body: <p>I'm now using NetBeans as my IDE-of-choice, and it has a plugin for UML modeling. In the class diagram, there are model elements known as <code>Boundary Class</code>, <code>Control Class</code>, and <code>Entity Class</code>. However, I can't find a good definition of them, but I did find <a href="http://www.developer.com/design/article.php/10925_2206791_2" rel="noreferrer">this site</a> on UML Class Diagrams.</p>