GraphQL Mutation

Where a query reads data, a mutation writes it — creating a record, updating a field, deleting an entity. Mutations are still just GraphQL operations with a schema-defined shape, but by convention they're named as verbs (`createPost`, `updateUser`) and typically return the changed object so the client can update its local state immediately.

• —Separating queries from mutations in the schema makes intent explicit — anyone reading the schema can see what changes data and what doesn't.
• —Returning the updated object from a mutation lets the client refresh its UI without a separate follow-up query.
• —Mutations need the same authorization checks as any write operation — GraphQL's flexibility doesn't replace access control.

This is the exact lesson that covers this term in depth — with examples, diagrams, and a hands-on exercise.