Multiplayer

Single player and LAN host: the mods run in the host's game and its integrated server, so a server-side hook applies to every player of the world.
Joining a server: client-side hooks run locally. Configuration requires matching both-side mod ids and versions; a refusal names the missing, extra or different-version mods (configuration policy).
Dedicated server: native mods run in a standalone engine export built with --server-output, not in an instance build (--server-output conflicts with --instance and needs an explicit mod FOLDER). See Standalone server export.