GraphQL is an open-source data query and manipulation language for APIs and a query runtime engine.
GraphQL enables declarative data fetching where a client can specify exactly what data it needs from an API. Instead of multiple endpoints that return separate data, a GraphQL server exposes a single endpoint and responds with precisely the data a client asked for. Because a GraphQL server can fetch from separate data sources and present the data in a unified graph, it is not tied to any specific database or storage engine.