A: The Internal GraphQL Server can be invoked within your application, using PHP code. You can use it to trigger the execution of a GraphQL query whenever some action happens, to perform some related task (such as sending a notification, adding a log entry, validating a condition, etc).

Persisted queries are normal GraphQL queries, however they are stored in the server and accessed under their own URL, thus emulating a REST endpoint. They provide the advantages of both REST and GraphQL. They allow you to execute tasks directly within the wp-admin, without deploying any code. (Eg: the automations are executions of persisted queries, that you code directly in the wp-admin)

Docs:

- https://gatographql.com/extensions/persisted-queries
- https://gatographql.com/extensions-reference/persisted-queries
- https://gatographql.com/extensions/internal-graphql-server
- https://gatographql.com/extensions-reference/internal-graphql-server/