The goal of this chapter was to quickly introduce you to the concepts of Relay and GraphQL prior to the final chapter of this book, where we're going to implement some Relay/GraphQL code.
Relay is yet another approach to the state management problem in React applications. It's different in the sense that it reduces the complexities associated with the data fetching code that we have to write with other approaches to Flux, such as Redux.
The two key aspects of Relay are declarative data dependencies and explicit mutation side effect handling. All of this is expressed through GraphQL syntax. In order to have a Relay application, you need a GraphQL backend where the data schema lives. Now, onto the final chapter, where we'll look at these Relay/GraphQL concepts in more detail.