React Router is a popular library for managing navigation in React applications. It allows developers to create single-page applications (SPAs) by enabling dynamic routing, which means users can navigate between different views without reloading the entire page. This enhances the user experience by making the application feel faster and more responsive. With React Router, developers can define routes that map specific URLs to components. This makes it easy to organize the application's structure and manage different views, such as home pages, user profiles, or product listings. Overall, it simplifies the process of building complex applications with multiple pages.