I’m not sure I understand what you just said. It allows users to request movies or TV shows and shows them what your media player already has available. If you interested it with the arrs it will add it and optionally initiate a search. docs.seerr.dev
The *arr suite is a bunch of media management software that can integrate with different sites to download torrents. This lets your users (friends and family) request stuff to download without having access to your *arrs
So you run radarr to pickup movies and sonarr for shows, instead of having both open for all of your users, you just run jellyseerr and you and your users can use that to discover and send requests to the other *arrs