How do the basic Navigator.push and Navigator.pop methods let you navigate to a new screen and then properly return back to the previous screen?

Navigator.push adds a genuinely new screen onto the top of your app's own internal navigation stack, properly and automatically transitioning to display that particular new screen, while Navigator.pop removes the genuinely current topmost screen from that same stack, correctly returning the user back to whichever screen was previously genuinely displayed directly underneath it, and this basic underlying stack based model, where screens are genuinely pushed on and popped off much like a simple stack of individual physical cards, forms the genuine foundational basis for essentially all navigation throughout Flutter.

Navigator.push(context, MaterialPageRoute(builder: (context) => DetailScreen()));

// Later, on the detail screen
Navigator.pop(context);