title: Clarify the difference and connection of canvas, frame, pane and panel
body: <p>I'm quite confused and I when I try to find an answer with google I get bombarded with tutorials.</p>
  
  <ul>
  <li>What is the purpose of each one? </li>
  <li>How are they connected?</li>
  <li>What is the purpose of the connection?</li>
  </ul>