Roon: everything you need to know

There have been a number of threads started, and hundreds of posts, asking 101 level questions about Roon.

This overview from WHAT Hi*Fi? is an excellent one. I believe this may / will be valuable to those exploring, considering, and/or starting out with Roon.

I respectfully request posts in this thread focus On Learning about Roon.

There are (other) numerous, better suited threads where opinions (both pro and con) can be expressed, shared and discussed. Thanks!
My 1 tip:

Roon exaggerates how much CPU power you need for it. Unless you are upsampling, especially to DSD, you do not need a lot of CPU power for the core.
+1 and Thanks @ erik_squires and @yyzsantabarbara 

You are welcome, @tuberist  
I’ll add that having enough RAM is important. If anything, push for more RAM if purchasing / building a Roon Core. My recommendation is to push for 128GB over 64GB should your chipset / motherboard accommodate this.