Global World Data is data that is stored and synced between all clients such as Pillager raid information or Boss infomation.
Mojang uses PersistentStates to store global world data. You can check the Persistent States page for more information on how to save your data for use across different play sessions or server restarts.
Cardinal Componenets, a library designed to allow developers to store data in any class and sync between clients and servers, can simplify this workflow. More infomation on Cardinal Components can be found here: https://github.com/OnyxStudios/Cardinal-Components-API