Resolvers are the code that actually figures out where GraphQL gets the requested data from.
A resolver is a function that tells GraphQL how to resolve a field in the schema. When a client asks for a field, GraphQL uses the appropriate resolver to retrieve or calculate the value, often by calling a database, another service, or application logic.
Resolvers can also resolve nested fields, accept arguments, access context, and work with authentication information. Understanding how GraphQL execution moves from a schema to resolvers is one of the most important concepts for building GraphQL APIs.
What you'll walk away knowing