Yes, that was a very concise and complete reply. Thanks a lot, pavroo.
I have another set of questions relating to Sparky 3.2 E17, which impressed me so much I installed it immediately on a desktop machine with less RAM but am now having trouble getting around in it. (Open applications seem to disappear and I'm not sure yet whether they have crashed or are still open but hidden).
The panels of both Mate (the most complete, IMO), and xfce allow users to add menus that provide a means to see what is open and navigate within the system. I probably need to take a look at an E17 tutorial.
One of the reasons I installed it is, like Openbox, E17 is also a window manager and the developers have stated their intention to produce a Wayland compatible version, which is an issue that Openbox must also deal with also, since it is an X11 window manager, and X11 is likely to be replaced by Wayland in the not too distant future.
If I don't resolve this after finding an E17 Tutorial I'll post another E17 specific thread.