Clean Architecture in .NET 10: The Domain Layer — Entities That Actually Have Behavior

This part focuses on building the Domain layer, emphasizing business rules and value objects. The domain layer should encapsulate core business logic, independent of technical concerns. Value objects, like the `Tag` example, are used to wrap primitives with validation and behavior. The text advises against unnecessary wrapping of simple data types. The concept of a `ModelType` value object is introduced, offering flexibility beyond simple enums. A `Collection` entity is created, showcasing storing IDs instead of full entities for performance. It also discusses the "Anemic Domain Model," acknowledging that some domains are primarily CRUD. Validation is handled at different layers, including the domain and application layers, for defense in depth. A refined `Prompt` entity incorporating the `Tag` value object is presented. Testing domain logic is highlighted as simple and focused. The summary concludes with key takeaways and hints at the upcoming Application layer.