A question about the relation between different kind of themes on the Gnome Horizon!

[Jacky Lau Hok Yan <zenithlau i-cable com>]

Hi,

To be frank, I love gnome. As for the lovely appearance, and the solid
experience (My eng. is bad. may be there is a better wording to describe
it :) )

I am quite wondering about the inter-relation of different kind of themes.

In my knowledge, there is GTK2 themes, icon themes, metacity themes,
metathemes. SVG themes.
I also know that, gtk2 themes, icon themes, and metacity themes are
quite standalone.
i.e. You untar it, and configure with gconf-editor. that's it. Right?

How about SVG theme?
Is it also a kind of gtk2 theme engine?

And how about metathemes?
I think I would like to know a little bit more, so that I can have a
clear picture..

Also, is the gnome-themes-extras the only pkg which deliver themes for
gnome users?

Thanks, and
Regards
Jacky Lau