So if I give you the game for free, it is backwards compatible?
I bought the game. I don't have to buy the game again. I stick in my PS4 game disc into the PS5 and it plays. If you give me a PS4 game for free and I stick it into the PS5 it still will work. You paid for it. My Xbox or Xbox 360 or Xbox One games that I have paid for or got free from a friend that he paid for will work when I put them in without having to pay again. That's backwards compatible. As long as I'm not paying again to play these same games it's backwards compatible.
...to avoid getting banned for inactivity, I may have to resort to comments that are of a lower overall quality and or beneath my moral standards.