Desktop Thundermail Calendars in Windows 11

I am early days learning to use Desktop Thundermail Calendars in Windows 11. I have several calendars showing up in my list of Calendars. Home, My name (seems to draw input from 2 emails I have connected), New Holiday, Thundermail Calendar, My wife's name (seems to draw input from 2 emails I have connected that she wants me to monitor as she rarely uses them). I would like to get a basic explanation of what each of these calendars are and how they may relate to each other. This may already exist somewhere? For example: what is the difference between Home and Thundermail Calendars? Why do my 2 other emails only form one combined calendar?