What Is GraphQL?: GraphQL is a query language for your API and a server-side runtime for executing queries by using a schema type system you defined for your data. GraphQL is not tied to any specific programming language(like NestJS, Java, .NET, etc) or database or storage engine. How GraphQL Different From Rest API: GraphQL exposes a single endpoint. Http-Post is the only Http verb recommended by supported by GraphQL API. Client applications(consumers of GraphQL API) can give instructions to GraphQL API about the response data. Code First vs Schema Approach: Code First Approach: In Code First Approach we use Typescript class to which need to apply GraphQL decorator on top of classes and also on top of properties inside of the class. These decorators help to auto-generate the raw GraphQL Schema. So in Code First Approach we no need to learn or concentrate to write the GraphQL Schema. Schema First Approach: GraphQL SDL(schema definition language) is a new syntactic query type language,