A casino operator runs the site, manages player accounts, payments and support,...
https://wiki-byte.win/index.php/How_Do_Casinos_Mix_Games_From_Multiple_Providers_in_One_Catalogue%3F
A casino operator runs the site, manages player accounts, payments and support, and chooses which games to list. A slot provider makes the game software and sets its rules, such as paylines and bonus features