Settings are places... but it isn't always so simple. That place is where your MC interacts with the plot and other characters, and often the setting itself is vital to that conflict.

You can't write the same story with three characters in a library or a local gym or a public school and have it be the same story. At least, not if your setting is integral to what you're writing.
https://www.writerswrite.co.za/5-essential-exercises-for-writing-about-setting/

Think about it another way: I'm writing this story on the moon in the year 2060, or a public library in Montana in 1981, or a public bath in Roman times. You may be able to set up the same conversation, but the different settings, eras, and backdrop of history (even future history, in the case of the moon) as well as the language/accent/dialect used in these places can make them much richer if you bring that setting to life.

From the Calendar:
(1) Create a list of settings in a format easy to edit and expand.
(2) Add brief descriptions, drawings, images or Google Maps coordinates (find the location on Google Maps/Earth and record the URL) for each.

NOTE: You can revise this list at any time, so this revision is not expected to be fully accurate or complete.

I always revise the list as I go. I have often been remiss in good descriptions, but my characters interact with things and teach you what they are while they're going. So that terrifying word zatepan suddenly becomes a game that comes from a culture of one of my ship's crew, and then has spread through the galaxy as a very misunderstood gambling game. That's part of my definition list, but the board and pieces stay in the galley, which becomes part of the place where the ship's crew lives in their downtime.

https://thenarrativearc.org/setting

https://www.free-training-tutorial.com/writing/setting.html