The route name is an important piece of navigation. It is the identification of the route with its manager, the Navigator widget.
We can define a series of routes with names associated with each of them. It provides a level of abstraction to the meaning of a route and a screen. By the way, they can be used in a path structure; in other words, they can be seen as subroutes.
Have a look at the home property of the WidgetsApp. It implicitly sets the home route widget for the Navigator widget. It is referred to as the '/' path.