How difficult would it be to have a peertube to only host url’s to the various video’s. So lets say an instance holds the url to a video not hosting the actual video that would be for instance the creator of the video on his/her own hosting.
Please let me know if I have not put my question clearly.
As far as I understand the documentation this is exactly what happens when you follow another PeerTube instance
Following an instance will display videos of that instance on your pages (i.e. « Trending », « Recently Added », etc.) and your users will be able to interact with them.
Videos will only be stored on your instance if you set-up redundancy for the remote instance.
So if I understand correctly you are able to have a site which just contains links to videos?
Yes, just not any links. They must be from another PeerTube site which you follow.
oh sorry I did not understand « if you set-up redundancy for the remote instance. » in tdi post.
Sorry 
« redundancy » is used for remote PeerTube instances you follow, from which you want to host the recent videos (how exactly is configurable) to share bandwidth.
So when you follow a remote instance with yours, you make their content more visible as it will be shown under « discover », « recently added » and « most liked ». But the video will be loaded from the remote instance.
If you then configure the redundancy your instance would also hold the video files and serve them. If you don’t activate the redundancy, you just give a boost to the visibility of the other instance content.
Thank you for your kind explanation I understand now