What is GraphQL? GraphQL is an open‑source query language for APIs and a server‑side runtime. It provides a strongly‑typed schema to define relationships between data, making APIs more flexible and predictable.

Understanding the Context

And it isn’t tied to a specific database or storage engine — it works with your existing code and data, making it easier to evolve APIs over time. GraphQL supports reading, writing (mutating), and subscribing to changes to data (realtime updates – commonly implemented using WebSockets). [10] A GraphQL service is created by defining types with fields, then providing functions to resolve the data for each field. The types and fields make up what is known as the schema definition.

Key Insights

The functions that retrieve and map the data are called ... GraphQL: APIs for humans and agents GraphQL is the developer-friendly query language for the modern web. It transforms how apps fetch data from an API, enabling you to get exactly what you need with a single query —instead of wrangling responses from a patchwork of REST endpoints. With a strongly typed schema at its core, GraphQL helps you define relationships between data across any number ... Learn what GraphQL is and how it works.

Final Thoughts

Discover topics from the most basic concepts, like how GraphQL works, to usage topics like GraphQL schema, mutation, subscription, and many more. Discover how GraphQL supports real-time data with subscriptions and how to use them effectively at scale. See how GraphQL ensures query correctness through validation rules and how common errors are detected early. Learn how resolvers power GraphQL execution and how the server processes and returns data for each query.