The Angular architecture section of Chapter 10, Angular ASP.NET Core Project Template, gives the basics of Angular routing, and the Angular modules section of the same chapter also explains how to define routes in external modules. This section gives more details and introduces some advanced routing features, such as route guards and module lazy loading.
Each application must have just a single router that must be defined withRouterModule.forRoot(...) in the main application module that accepts an array of routes as its argument. If other modules define their own routes, they must do that with RouterModule.forChild(...), which doesn't add another router, but which allows just the definitions of other routes to be merged into the ones of the unique router defined in the application main module. Routes defined in other modules are added in the same order...