Orion question SIAP

Trying to understand Orion.Have free account installed on Stremio.So is it that it will bring up links but if you don’t have RD or some other service installed on it the links won’t play?

Orion is a stand alone and shows links that for me do play. I only have the free one as I’ve used it twice this last year, and then only to see if it even works. The links I get are mostly SD.