ROON Ready simply means that a streamer will work as a ROON endpoint and stream (offline music/Tidal/Qobuz/KkBox) from a ROON Core.
The ROON Server is to be installed on a computer (or Qnap/Synology NAS). There's also a ROON ROCK, which is a dedicated NUC solution. There are a few ready made solutions for the Roon Core like the Roon Nucleus, the Silent Angel Rhein Z1, etc etc. But those are expensive solutions.
Basically, you need a Core/Server, for the Endpoint to work. (Some Cores/Servers can be used as endpoints too, but ROON does not recommend that).