A casino operator runs the site and manages player accounts. A slot provider...

https://tango-wiki.win/index.php/Why_First_Impressions_Can_Be_Misleading_with_Slot_Games

A casino operator runs the site and manages player accounts. A slot provider creates the games. Provider names show who made each title and help you compare catalogues. Visuals and sound can vary, but they do not change the game rules.