REST is all about endpoints that perform specific queries or operations. This works fine, but the client is limited by which queries have been exposed. What if the back-end exposed the data, but the client could decide which subset of data it needed, or how to interact with that data? That’s the promise of GraphQL — simplify the back-end, give the client more power, and make it easier to evolve APIs. In this talk, we’ll explain what GraphQL is, how it works, and look at a JavaScript client and a Java back-end.

GraphQL for Java Developers