apollo-server/docs/source/essentials/building-schema.md

title	description
Building a schema	The why, what, and how of building a schema

The schema is the core of your GraphQL service. It validates operations, routes queries to data, powers next generation develoment tools, and is the contract between clients and your service. With Apollo Server, building a schema is as easy ad describing your schema and joining it with some simple functions to return the data.

Type Definitions

Resolvers

Viewing your schema