What happens in the mantle?

Excuse me, could you please elaborate on what happens in the mantle? I'm quite fascinated by the concept but still a bit hazy on the details. Is it related to geological processes? Or does it involve some sort of mysterious, supernatural forces? I'm eager to learn more about this intriguing subject. Could you break it down for me in a way that's easy to understand, perhaps with some examples or analogies? Thank you so much for your help!