Web Development
Intermediate
What is GraphQL?
A query language for APIs that lets clients request exactly the data they need, reducing over-fetching and under-fetching.
GraphQL, developed by Facebook, provides a single endpoint where clients specify their data requirements in queries. Unlike REST (multiple endpoints, fixed responses), GraphQL returns exactly what is requested — no more, no less.
Key concepts include schemas (type definitions), queries (read data), mutations (write data), and subscriptions (real-time updates). Tools include Apollo (client/server), Relay, and GraphiQL (interactive explorer). Trade-offs include complexity and caching challenges.
