This server is called Adornment and it is a modded Minecraft world where players try to build up full civilizations together.
You join a group and work as a team to grow your own civilization. You can also start your own group if you want and invite other people to join you. The whole idea is to see different civilizations rise up and build cool stuff.
The owner is 18 and is looking for more people who like this kind of civilization style server. It feels like a place where small groups can hang out build bases and slowly turn them into full kingdoms.
You can either join the owner and help with their civilization or you can make your own and see how far you can go.
