In this chapter, you learned that React can be rendered on the server, in addition to the client. There are a number of reasons for doing this, such as sharing common code between the frontend and the backend. The main advantage of server-side rendering is the performance boost that you get on the initial page load. This translates to a better user experience and, therefore, a better product.
Then, you progressively improved a server-side React application, starting with a single-page render. You were also introduced to routing, client-side reconciliation, and component data fetching to produce a complete backend rendering solution using Next.js.
In the next chapter, you'll learn how to implement React Bootstrap components to implement a mobile-first design.