## What you'll build In this tutorial, you'll define a GraphQL schema that you can use to provision backend resources, store data locally, sync to a cloud database, as well as receive updates over a realtime subscription. [GraphQL](http://graphql.org) is a data language that was developed to enable apps to fetch data from APIs. It has a declarative, self-documenting style. In a GraphQL operation, the client specifies how to structure the data when it is returned by the server. This makes it possible for the client to query only for the data it needs, in the format that it needs it in.