Hi @JVermunt 
Yes, that’s right. The Associations API has clear definitions between endpoints that manage the definition of association types (e.g. making it possible to associate individual records) and those that manage associations between individual records.
To retrieve associations between individual records, you’ll want to use the “Retrieve associated records” endpoint (see “Retrieve associated records” section in this documentation).
I hope that proves helpful. Please let me know if you have any follow-up questions.