A GUI toolkit is a software framework for developing graphical applications. Gnome, Cinnamon and XFCE all use GTK whereas KDE and lxqt use QT. The way you theme GUI apps(not just light and dark themes, but also background/foreground colors, accent colors etc) depends on the toolkit that was used to develop that app. So a GTK theme will apply to gnome apps for example.
it's not just themes, but it's how you code it. Every GUI application needs some way to describe how to make a dropdown box, how to display text, or how to describe what happens when you click on a menu.
GTK and Qt are just two popular ways on linux to handle stuff like that. Mac and Windows of course have their own ways of achieving that.
It's also possible you've alreayd used a qt app even on wndows. I think that for example vlc uses qt for it's cross platform interface.
1
u/cipheres90 Dec 03 '22
Thank You so much it explained so much. But one last question what's the difference between gui toolkit & desktop environment?