There exist many unique object type arrangements to represent any system and the art lies in keeping the object type organization simple, easy to understand, flexible to future change requests, and scalable.
Each object type has a structural definition that further defines what data we are storing and retrieving from the server. This standardizes the objects that are stored in the database and gives indication to the system how to treat the data. Importantly, objects can reference other objects in various ways. For example, a Book object may reference an Author object in the library’s system and a medical form object may reference two Person objects for its doctor and patient fields.