To have further insights on such query languages, see:
API Reference Guides
The API Reference Guides for REST and GraphQL APIs are accessible via the account’s application interface and contain information about every API supported by Marketing Cloud.
To access the API reference guides, click on your username and select Connections.

On the Connections page, select the REST API tab to see all the supported REST APIs, and the GraphQL API tab to view all the supporting GraphQL APIs.

Request Authentication
Marketing Cloud's API uses API Keys to validate requests from several IP applications. The Settings tab allows you to generate, view, and administer your API keys. For more details, read our API Keys article.
Native Code Libraries
Marketing Cloud also offers native code libraries, which include some of the web's most popular programming languages, such as: