> For the complete documentation index, see [llms.txt](https://docs.adsecure.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.adsecure.com/docs/graphql/concepts.md). # Concepts ## Schema A schema defines a GraphQL API's type system. It describes the complete set of possible data (objects, fields, relationships, everything) that a client can access. Calls from the client are [validated](https://graphql.org/learn/validation/) and [executed](https://graphql.org/learn/execution/) against the schema. A client can find information about the schema via [introspection](/docs/graphql/forming-calls.md#discovering-the-graphql-api). A schema resides on the GraphQL API server. For more information, see "[Discovering the GraphQL API](/docs/graphql/forming-calls.md#discovering-the-graphql-api)". ## Field A field is a unit of data you can retrieve from an object. As the [official GraphQL docs](https://graphql.org/learn/schema/) say: *The GraphQL query language is basically about selecting fields on objects.* The [official spec](https://spec.graphql.org/) also says about fields: *All GraphQL operations must specify their selections down to fields which return scalar values to ensure an unambiguously shaped response.* This means that if you try to return a field that is not a [scalar](/api/graphql/scalars.md), schema validation will throw an error. You must add nested subfields until all fields return [scalars](/api/graphql/scalars.md). ## Argument An argument is a set of key-value pairs attached to a specific field. Some fields require an argument. [Mutations](/docs/graphql/forming-calls.md#about-mutations) require an input object as an argument. ## Connection Connections let you query related objects as part of the same call. With connections, you can use a single GraphQL call where you would have to use multiple calls to a REST API. It's helpful to picture a graph: dots connected by lines. The dots are nodes, the lines are edges. A connection defines a relationship between nodes. ## Edge Edges represent connections between nodes. When you query a connection, you traverse its edges to get to its nodes. Every `edges` field has a `node` field and a `cursor` field. Cursors are used for [pagination](https://graphql.org/learn/pagination/). ## Node Node is a generic term for an object. You can look up a node directly, or you can access related nodes via a connection. If you specify a node that does not return a [scalar](/api/graphql/scalars.md), you must include subfields until all fields return [scalars](/api/graphql/scalars.md). For more information about performing queries, see "[Forming calls with GraphQL](/docs/graphql/forming-calls.md)". --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.adsecure.com/docs/graphql/concepts.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.