“I'm not all that familiar with how Steam works, only that it allows me to find and use games on my Mac for work that I would otherwise not have access to via iOS's App Store... I've seen games listing all 3 symbols (Apple, Windows, Steam), or just Apple, or just Windows, or like the example pictured in this thread, etc.

I DO understand the logos on the games listed in the store indicate what OS the game can be played on, but what's the significance of the steam symbol in this context.

My question for clarification: would combo of Windows + Steam symbol indicate it I could still launch this game on my Mac AS LONG AS I launch it from my Steam Library...?

(...as opposed to downloading it to a Windows machine, and then launching it directly as its standalone application without involving Steam at all... I have done this with another game in the past)

Or is "SteamOS + Linux" a completely separate machine altogether?”

seeking clarity on this question.