Modeling the Domain: Entities, Value Objects, Aggregates

In DDD-based .NET Core architectures, the domain model is built from entities, value objects, and aggregates.

Entities: Have an identity that persists over time.

public class Order
{
    public Guid Id { get; private set; }
    public OrderStatus Status { get; private set; }
}

Value objects: Immutable, equality by value.

public record Money(decimal Amount, string Currency);

Aggregates: Consistency boundary with a single aggregate root.

All external references go through the root, enforcing invariants.

Architecture impact: Correct aggregate design reduces bugs, enforces invariants, and simplifies persistence.

Reference:

Microsoft: DDD Aggregates in Microservices

https://learn.microsoft.com/dotnet/architecture/microservices/microservice-ddd-cqrs-patterns/ddd-oriented-microservice