Bungee-Cord Servers

Hello! I am setting up a network of Bungee-Cord servers and I understand that each server you go to is another server. I was wondering how I can get certain things like Ranks, and Permissions to stay the same as players jump from server to server, I know there has to be a way since I see servers with things such as friend list, or points remain as they jump around though Bungee, How do they have this set up? Any help would be awesome!