nsIXULWindow vs nsIDOMWindow

I was wondering the differences between nsIDOMWindow (returned by Services.wm.getWindowEnumerator and nsIXULWindow returned by Services.wm.getXULWindowEnumerator.

The reason I ask is because i heavily use the windowListener (https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIWindowMediator?redirectlocale=en-US&redirectslug=nsIWindowMediator#addListener%28%29)

I created an example on MDN but don't understand the difference between the two windows. I was thinking if I do i can make a better example. Thanks

Solution

NSIXULWindow is a XUL Application Object Model(AOM) window:

#document
  window                 main-window
    ...
      browser
        #document
          window         myExtensionWindow

Just as HTML is reflected in the DOM as nodes like link, layer, and img, XUL is reflected in the Application Object Model in the hierarchy of XUL widgets: browser, menu, menuitem, and so on. The DOM and the AOM form a kind of continuum, the whole of which is manipulable from the standards upon which XUL is based.

NSIDOMWindow is a HTML Document Object Model(DOM) window:

When a XUL window contains a widget capable of displaying a page, such as <browser> or <iframe>, the document in that widget is, naturally, separate from the document of the chrome window itself. There also is a Window object for each sub-document, although there's no window in a common sense for the sub-document.

The same holds for chrome windows opened inside a tab of <tabbrowser>. The elements above the chrome document opened in the tab are separate from your chrome document.

References