[[Domain Event|Domain Events]] capture significant occurrences within a domain, while [[Entity|Entities]] represent mutable concepts, maintaining consistent identity, protecting invariants, and enforcing business rules. Although Domain Events may be triggered by [[Command|Commands]] that involve specific Entities, they should not depend on or reference Entities directly. This separation ensures that Domain Events remain independent of the internal structure of Entities. Domain Events are immutable, while Entities can change. Keeping them distinct prevents unintended side effects, such as changes to an Entity affecting the state of a related Domain Event. Referencing Entities within Domain Events can complicate serialization and lifecycle management, especially in distributed systems or [[Event Sourcing]] architectures. It also simplifies testing. Rather than referencing an entire Entity, Domain Events should carry only the relevant data, either as a [[Value Object]] or a snapshot of the Entity's state at the time the event occurs. They can refer to Entities using identifiers, and if more data is needed, the event can be enriched with additional information as it propagates through the system. [[Domain Service|Domain Services]] can mediate the interaction between Domain Events and Entities, allowing the event to interact with the entity without holding a direct reference to it.