chat – How does an irc demon like Charybdis work?

I'm pretty new to IRC and I dig in to try to understand it.

I'm running CentOS 7 on a virtual machine and I've installed charybdis-4.1.1 and atheme-7.2.10-r2 using this wonderful guide. However, although the guide tells me how to install it, he does not really tell me how it works, it's a bit my goal.

What I had in mind was to set up a server and analyze it under the guidance of an online tutorial. However, I have not found any online material that explains how certain files work. I've tried reading the github documentation page, but that does not really tell me how it works.

I understand that most people use irc clients instead of installing and maintaining a server, which may partly explain the inability to find hardware. So … could a benevolent soul help me understand how it works? Or maybe provide a link to a charybdis tutorial? Thank you so much!!