The book starts by introducing the reader to React, what it is and why you need a library like React to work with medium to large scale applications. We then move on to implementing simple client-side programs with React, uncovering modern React practices like React hooks and diving deep into various kinds of hooks. We then move to implement React on the server using Server-Side Rendering to bring benefits of the SEO world to the dynamic rendering nature of front-end libraries. For this, we use Next.js, a very popular implementation of Server-Side Rendering which comes with tons of good practices already baked in. We also take a look at how Progressive Web Apps can be created out of existing React codebases and what benefits it provides us. Finally, we end the book with some React internals (how to React works) and some bleeding-edge features in React which are expected to roll out in 2-3 years fully and would impact how to React works under the hood.