Route Guards

Route Guards are essentially Angular services (i.e. classes with @injectable decorator) that you can define and use to control user's access to some routes i.e. to allow or deny a user from navigating to some routes.

A Route Guard Service Class need to implement one of the following 4 interfaces:

1. CanActivate	To control access to some route
2. CanActivateChild	To control access to children of a route
3. CanLoad	to control loading of some lazy-loaded module
4. CanDeactivate	to control if user can leave a route. This can be used to prevent user from accidentally moving to some other part of the app without saving changes in the current view/page.

How to implement Route Guards - https://alligator.io/angular/route-guards/