Meta

[The Mike]

I have a show from YouTube, where some of the movies are already shown with proper thumbnail and description, while other doesn't.

When i edit the meta data, does it go into the movie or just a jellyfin data file?

If I manually edit the meta info, can it dissappear when I try to refresh meta data across all movies and shows?

[TheDreadPirate]

Jellyfin does not modify your media files. Any changes are saved to Jellyfin's data directory and/or database.

Depending on which refresh type you select can affect existing metadata different. The standard "update" refresh will only look for new items.