The physical Standard Edition of Call of Duty: Vanguard for PlayStation 5 or Xbox Series X includes a game disc and offers higher framerates, hardware-based graphical improvements, shorter load times, and other advantages compared to the PlayStation 4 and Xbox One versions of the game.
Yes, you can play almost all PS4 games (physical and digital) on the PS5 as well. And this game is one of many that is compatible for backwards compatibility on PS5.