Refreshing Metadata for a library or individual item causes the metadata for the item to be refreshed, even if it already has metadata. Moved files from one location to another.

Added or removed folders from the library source.You should Scan Library Files if you have: You can think of scanning as “check for new or changed content and get metadata for it if needed”. If it finds new or unmatched media, it then pulls it into the library and fetches metadata for it. Scanning a library makes the Plex Media Server check its folders and sub-folders for new or removed media. Scanning and refreshing a library both have to do with getting content into the library. Scan Library Files vs Refresh All Metadata Scanning and Refreshing a library do different things. You can Refresh or Scan libraries to bring them up-to-date. As time goes on, you’ll add and remove media to the libraries or make other changes that mean the library is no longer up-to-date.

Once a library has been created, it is processed by your Plex Media Server so all the media items are matched and metadata is gathered.

Plex media server update library