Dispose vs Dispose(bool)

I am confused about dispose. I am trying to get my code disposing resources correctly. So I have been setting up my classes as IDisposable (with a Dispose method) them making sure that the Dispose method gets called.

But now FXCop is telling me lots of stuff about disposing = false and calling Dispose(false).

I don't see a Dispose method that takes a bool. Do I need to make one? If so, why? Why not just have a method that gets called when it is disposing?

I saw some code here: CA1063: Implement IDisposable correctly - Microsoft Docs that shows how to make a Dispose method that takes a bool. It says it is for native vs managed resourses. But I thought the whole point of dispose was for unmanaged resourses only.

Also, the line that FXCop is complaining about is this:

~OwnerDrawnPanel()
{
    _font.Dispose();
}

It says:

CA1063 : Microsoft.Design : Modify 'OwnerDrawnPanel.~OwnerDrawnPanel()' so that it calls Dispose(false) and then returns.

But Font does not have a Dispose(bool) on it (that I can find).

To sum it up:

Why do I need a Dispose(bool)? and if I do, why doesn't Font have it? and since it does not have it, why is FXCop asking me to use it?

Thanks for all the great answers. I think I understand now. Here is

The answer as I see it:

Disposing of "unmanaged" resources falls into two categories:

1. Resources that are wrapped in a managed class (ie Bitmap, Font etc), but still need Dispose to be called to clean them up properly.
2. Resources that y