Using Jellyfin in LAN

[Efficient_Good_5784]

1. Does Jellyfin work via LAN, and if so, does it require additional settings or does it work via LAN by default?

Works by default.

2. When it says "online," does that mean I can use it anywhere, or do I need to be on the same network?

By default, you'll only be able to use it on the same network.

Jellyfin works when your internet is down since it doesn't run on the internet, it runs on your local network.
As long as your router, ethernet cables, and wifi connection remain working, Jellyfin will be usable on your network.

3. Can I restrict the use of internet data for streaming and limit it to media info, tags, and covers?

By default, Jellyfin will only reach out of your local network to obtain metadata by using file and folder names. It won't actually stream the media anywhere outside of your local network.