GraphQL
https://en.wikipedia.org/wiki/GraphQL

Official GraphQL Documentation
https://graphql.org/learn/
This is the best place to start for understanding the core concepts of GraphQL. It provides detailed explanations of queries, mutations, schemas, types, and more.

How to GraphQL
https://www.howtographql.com/
This is an in-depth tutorial site offering free courses on GraphQL, covering topics like the basics, advanced features, and specific implementations for various programming languages.

Apollo GraphQL Documentation
https://www.apollographql.com/docs/
Apollo is one of the most popular GraphQL clients, and their documentation includes a lot of information on best practices, caching strategies, and setting up GraphQL on both client and server sides.

GraphQL by Example on FreeCodeCamp
https://www.freecodecamp.org/news/tag/graphql/
A beginner-friendly article on FreeCodeCamp that explains the fundamentals of GraphQL and compares it to REST.

Udemy and Coursera GraphQL Courses
https://www.udemy.com/topic/graphql/?
srsltid=AfmBOorBFyQDE_tsZhpUrlsFY9QLhPcNT-7QXYNpzqb2RmBiNnWTQLLK
Udemy and Coursera offer various paid courses that provide hands-on projects, particularly valuable for learning practical implementation.

YouTube Channels like Academind and Fireship
Both channels offer excellent tutorials on GraphQL. Academind has an “Apollo & GraphQL” series, and Fireship explains concepts quickly and concisely, like the “GraphQL in 100 seconds” video.