GraphQL lets clients request exactly the fields they need in one round trip — no over-fetching from RESTRepresentational State Transfer — a style for web APIs using HTTP methods and resource URLs. endpoints. Used with ReactA JavaScript library for building UIs — component trees and declarative rendering for the web. (RelayAn electrically operated switch using a magnet to open or close contacts — early digital circuits used thousands of relays., Apollo), mobile apps, and microservice gateways. Example: fetch a user's name and last three posts in one typed query instead of chaining RESTRepresentational State Transfer — a style for web APIs using HTTP methods and resource URLs. calls.

GraphQL changed how frontends fetch data and influenced APIApplication programming interface — a defined way for programs to talk to each other or to a service. design across the industry.

It decoupled client data needs from fixed RESTRepresentational State Transfer — a style for web APIs using HTTP methods and resource URLs. resource shapes — critical for mobile and varied clients.