The Evolution of CA: Hexagonal vs Onion vs Clean.

They are different names for the same core idea: separating business logic from infrastructure using concentric layers and interfaces.

Hexagonal (Ports and Adapters) focuses on the symmetry of the edges. Onion Architecture emphasizes the Domain Model at the center. Clean Architecture (Uncle Bob) combines these and adds specific names like 'Entities' and 'Use Cases' while stressing the dependency rule.