GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. GraphQL provides a complete and understandable description of the data in your API, gives clients the power to ask for exactly what they need and nothing more, makes it easier to evolve APIs over time, and enables powerful developer tools.
About GraphQL
GraphQL vs other API protocols
If you want to learn about the pros/cons of GraphQL vs other API protocols, we suggest reading Comparing API Architectural Styles: SOAP vs REST vs GraphQL vs RPC
GraphQL and Next Right Now
Next Right Now provides various presets. Some of those presets include a built-in GraphQL support.
In particular, the preset v2-mst-aptd-gcms-lcz-sty includes GraphQL support, using GraphCMS vendor. (gcms)