Layers

Clean Architecture has four layers:

1. Frameworks and Drivers (blue): UI, External Interfaces, DB, Devices
2. Interface Adapters (green): Gateways, Controllers, Presenters
3. Application Business Rules (red): Use Caes
4. Enterprise Business Rules (yellow): Entities

Example

Dependency Direction

No impacts from outer circles to inner circles!

Inner Layers do not know anything about outer layers.

Benefits:

• Use advantages of frameworks with less of their disadvantages
• Business rules testable without external elements
• Change UI without changing rest of system
• Business rules are not bound to any DB vendor
• Business rules do not know (and are independent of) the outside world