GraphQL enables a client to specify exactly what data it needs from an API, so instead of multiple endpoints that return fixed data structures, a GraphQL server exposes a single endpoint and responds with precisely the data a client asked for. If you want to wrap your head around GraphQL, here are two great resources to get you started. How to GraphQL is a free open-source tutorial to take your GraphQL skills from zero to production. Divided up into two parts, part one covers the core concepts of GraphQL while part two gives you a broader understanding of the GraphQL ecosystem.
Read more: https://www.howtographql.com/