React + GraphQL Tutorial — The Server

This tutorial is part of a full-stack tutorial series that teaches building an instant messaging app with React and GraphQL. The second part focuses on setting up a Node GraphQL server using Express and the `graphql-server-express` library. It covers topics such as writing a GraphQL schema, wiring up the schema to the server, setting up GraphiQL, connecting the GraphQL schema to real data, and writing resolver functions. The tutorial aims to provide a comprehensive understanding of building a GraphQL server from scratch.