If I download physical Xbox Series X game for my Xbox Series X can I play it on Series S?

I have the Xbox one X project Scorpio, I was told that the game can be downloaded in any serie X or serie S (included mine), thanks for the help!!

Game can only be downloaded on a Series S and Series X, but not an Xbox One X. Xbox One X is not the same as a Series X.

This is an incorrect assumption. You can insert an xbox one disc and download updates that may improve visuals and frame rates on Xbox Series X/S but in order to play you still need the disc unless you own the digital version of it.

Xbox Series X will utilize the Xbox One X version of enhancements while Xbox series S will use the Xbox One S enhancements.

You will not get a free game by borrowing or renting a physical version of a game and installing it on Xbox Series X/S.

I’m confused how will it work for both if one is physical and the other is digital

Both consoles are digital...it's just the Series S is Digital only whereas the Series X is both Digital and Physical.

75th Anniversary Edition Pre-Order can be downloaded to the Series S, the Series X and the Xbox One

Because on my Xbox series x, it only shows 'Optimized for series x/s' but if a xbox series x version of a game is NOT 'optimized' how would i know if I'm playing a series x/s version of a game?

Ok I have both versions of GTA downloaded on my series x the Xbox one version works fine on the series x I then downloaded the series s/x version on the series x I then launched the game and it gives the error message