Coxeter group

Imagine you have a bunch of toys that you can move around and arrange in different patterns. A Coxeter group is like a big group of friends who love playing with these toys and creating patterns together.

But there are some rules they need to follow. Just like you can't put two toy cars in the same place, these friends can't put two certain toys in the same position. And if they want to switch the order of two toys, they have to do it in a certain way. These rules are called "Coxeter relations."

These friends can create some really cool patterns using these toys, but they have to work together and follow the rules to do it successfully. That's what a Coxeter group is all about – a group of friends who create patterns using certain rules.