How to implement route navigation guards in Vue Router?

Route navigation guards allow you to perform actions before or after navigating to a route. For example, to check if a user is authenticated before entering a route:

const router = new VueRouter({
  routes: [
    {
      path: '/dashboard',
      component: Dashboard,
      beforeEnter: (to, from, next) => {
        if (userAuthenticated) {
          next(); // proceed to the route
        } else {
          next('/login'); // redirect to login
        }
      }
    }
  ]
});