gnome shell themes, extensions, gtk3 themes

[Marco Martin <notmart gmail com>]

Hi all,
I have a very newbie question (sorry if is not the right place for it
i'll ask again where you redirect me if so).
There used to be a website that collected various addons for GNOME,
https://www.gnome-look.org For several years unfortunately it didn't
see much development, but now it is in active development again and we
are recategorizing/cleaning its content.

Among the categories there are "Gnome shell themes" and GTK3 themes, I
am trying to understand the relationship between the two, if any.
If I understood correctly, both are CSS-based, but they are two
distinct things? A gnome shell theme applies to elements only found in
gnome-shell itself, not widgets of other applications. Looking at some
of them, it seems to be able to contain a gtk3 theme as well (in order
to have an uniform look between workspace and applications i guesS)
While, gnome shell extensions are javascript-based plugins that modify
the behavior of gnome-shell and don't have necessarly anything to do
with the "look" of it.

Did i got something wrong? anything to correct?

Also, if there is some other categories on gnome-look.org that we may
add that may be useful for GNOME or gnome-shell, we would be happy to.

--
Marco Martin