GraphQL
A query language for APIs where the client specifies exactly what data it needs. No over-fetching, no under-fetching. One endpoint to rule them all.
What is GraphQL?
A query language for APIs where the client specifies exactly what data it needs. No over-fetching, no under-fetching. One endpoint to rule them all.
GraphQL is a intermediate-level concept that sits in the API Design & Protocols area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "GraphQL" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
Learn GraphQL in depth
Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
Open the GraphQL lessonRelated lessons
Lessons that touch on GraphQL as part of a larger topic.
See also
Related glossary terms you might want to look up next.
REST API
An architectural style for building APIs using standard HTTP methods (GET, POST, PUT, DELETE). Resources are identified by URLs.
gRPC
A high-performance RPC framework by Google using Protocol Buffers and HTTP/2. Much faster than REST for service-to-service communication.
HTTP
The protocol powering the web. A request-response model where clients ask for resources and servers respond. Stateless by design.