Microsoft Exam PL-400 Topic 9 Question 11 Discussion

Visual representation of metadata can be useful, especially when you are trying to describe the relationship between entities in the system. You can use the Metadata Diagram sample code provided for Dynamics 365 Customer Engagement (on-premises) to generate the entity relationship diagrams.

You can create a diagram that shows a relationship for just one entity, or a complex diagram that includes dozens of related entities, including custom and system entities.

https://docs.microsoft.com/en-us/dynamics365/customerengagement/on-premises/developer/use-metadata-generate-entity-diagrams