A casino operator runs the site, manages your account, and decides which games...

https://fernandosmastercolumns.swiftnestly.com/posts/why-do-some-providers-reuse-the-same-ui-layout-across-games

A casino operator runs the site, manages your account, and decides which games appear in its catalogue. A slot provider makes the game itself, including its features, rules, visuals, and sound