These are the three Data Model objects that Reconciliation Rules operate across. Reconciliation rules tell Data Cloud how to prioritize values for unified individual profiles when there is conflicting information in the data model. For example, if two profiles have different email addresses, reconciliation rules can determine which one to use for the unified profile. Reconciliation rules can operate on the Individual object, which represents a person or entity, the Party Identification object, which represents an identifier such as a social media handle or a loyalty card number, and the Contact Point Email object, which represents an email address.
References: Identity Resolution Reconciliation Rules