How to create reusable elements using Panels

What's the difference?

Both Panels and Borders have their own markup file, but the markup is used in different ways:

The Border component inserts markup before and after its child components.

{panel}
   <html>
    <body>
     <div wicket:id="myBorder">
      <!-- Border markup -->
      <span wicket:id="myContent">content</span>
      <!-- Border markup -->
     </div>
    </body>
   </html>
{panel}

The Panel component inserts markup into the body of the tag.

{panel}
   <html>
    <body>
     <div wicket:id="myPanel">
      <!-- Panel markup -->
     </div>
    </body>
   </html>
{panel}