A GraphQL schema defines types. Each type — except for scalar types like Int, Float or String — has fields which define the relationship between this type and other types (one to one, or one to many). If you think about your schema in terms of a graph, types are the nodes of your graph, and fields are edges. Scalar types have no fields, so they form the leaf nodes of your graph. A GraphQL query is just an instruction for traversing the graph in a specific way, resulting in a tree.

When traversing a tree, you would start at the root, but a graph has no root so there is no logical starting point! That’s why every GraphQL schema needs to have a root query type: it’s the entry point into the graph. The fields of the root query type are links to the actual queries that your GraphQL server supports. This may sound confusing at first, but don’t worry about it, you can start using GraphQL just fine without understanding this detail.

#graphql #control #access control