Swing - JFrame - contentPane

Why does one add components to a JContentPane (instead of a JFrame)?I see explanations of how to do this but not why it is done this way.JFrame is derived from JComponent, as is JRootPane, so I'm not sure what the difference is.
[250 byte] By [allelopatha] at [2007-11-27 6:50:43]
# 1

The content pane is the actual part of the window where you can put the main content of your window, as opposed to the menu bar and other "reserved" areas of the window.

This page has an illustration that will explain it a lot better than I can here.

http://java.sun.com/docs/books/tutorial/uiswing/components/toplevel.html

kevjavaa at 2007-7-12 18:24:51 > top of Java-index,Java Essentials,Java Programming...
# 2

I've seen a Swing forum for Swing questions.

But people still seem to post all the questions in the Java forum.

Why did the forum designers create a Swing forum if everyone is still going to post Swing questions in the General Java forum?

Yet another mystery. Which one will be solved first, why people don't post in the correct forum or why a content pane exists?

camickra at 2007-7-12 18:24:51 > top of Java-index,Java Essentials,Java Programming...