What exactly are GLib and GObject?

I have been looking into the source code of python-mpdor and it mentions that it is

gobject-based, for easy event handling (in the high-level client class).

Can someone explain to me in simple terms what exactly are Glib and GObject and how do they interact with each other and what role it plays in event handling.

I tried searching for Glib and GObject but I didn't found any basic explanation for it. All the explanations I found are very technical and by technical I mean not suitable for a beginner.

Also, can someone point to some beginner tutorials/articles about Glib and GObject.