Schema: A GraphQL schema is at the center of any GraphQL server implementation and describes the functionality available to the clients which connect to it.
Query: A GraphQL query is the client application request to retrieve data from database or legacy API's.
Resolver Resolvers provide the instructions for turning a GraphQL operation into data. They resolve the query to data by defining resolver functions.
Type System defines various data types that can be used in a GraphQL application. The type system helps to define the schema, which is a contract between client and server.
Scalar Stores a single value
Object
Shows what kind of object can be fetched
Query
Entry point type to other specific types
Mutation
Entry point for data manipulation
Enum
Useful in a situation where you need the user to pick from a prescribed list of options
Mutation Type Mutations are operations sent to the server to create, update or delete data. These are analogous to the PUT, POST, PATCH and DELETE verbs to call REST-based APIs.
Mutation is one of the root-level data-types in GraphQL. The Query type defines the entry-points for data-fetching operations whereas the Mutation type specifies the entry points for data-manipulation operations.
Non-Nullable Type: field:data_type!
type Student { stud_id:ID!.
firstName:String lastName:String fullName:String college:College }
Qury: GraphQL query is used to fetch data. It is like requesting a resource in REST-based APIs. To keep it simple, the Query type is the request sent from a client application to the GraphQL server. GraphQL uses the Schema Definition Language (SDL)
Resolver is a collection of functions that generate response for a GraphQL query. In simple terms, a resolver acts as a GraphQL query handler
scalar or object
a resolver can also return other values