What is the difference between a 'Window Manager' and a 'Desktop Enviroment'?

I'm currenlty trying to understand what a desktop enviroment does. I hear terms like Xorg very often, how I understand it, it's a server that's running on my machine that allows other applications like a Desktop Enviroment to talk to the machine.

Then Desktop Enviroments, what I as a user percive is, is just the Window Manager, right? But from what I've read online a DE is more than just the graphics aka the Window Manager, correct?

I know this entire post is a bit unstructured, it's just because I don't really understand what I'm talking about. :(

My plan was to try out i3, and that's where the confusion started. Some people install i3 as a Desktop Enviroment, some install it on KDE or other DEs. And i3 has Window Manager in it's name, so if people say they install it on KDE do they just swap the KDE Window Manager with i3? And if people say they install i3 as a Desktop Enviroment they install it in place of KDE? But then again, I don't fully understand the difference between Window Manager and Desktop Enviroment.