Congratulations on completing the "React Router" course! You've acquired essential knowledge and practical skills for building powerful single-page applications with React Router. Let's recap the core concepts you've learned:

• Basic App Routing: React Router enables you to define routes in your application. You use the <BrowserRouter> component to wrap your app and the <Route> component to specify paths and the corresponding components to render when those paths match the current URL;
• Lazy Loading: You've explored the concept of lazy loading, a technique for asynchronously loading components or routes only when necessary. With React.lazy(), you can dynamically import components, boosting performance and minimizing initial loading times;
• Navigation: React Router provides various navigation components, including <Link> and <NavLink>. These components allow you to create links to different routes within your app. When users click on these links, React Router handles URL updates and renders the associated components.

With these fundamental concepts, you've laid a strong foundation for developing dynamic and navigable React applications. But don't stop here! The official React Router Documentation can assist with any additional concepts.