Too Long; Didn't Read
GraphQL (Graph Query Language) is an API-level query language. GraphQL is the alternative for REST made by Facebook. When facebook reached the limits of REST API, they had to make something breaking these limits. It helps network performance when the response contains a lot of data you don't need. It is also useful if your API supports different types of clients which want to call less and fetch more. We won’t talk much about Apollo architecture, we’ll learn everything needed by code examples.