Android Clean Architecture consists of several layers, each of which serves a specific purpose and is separated from the others to promote separation of concerns, maintain separation between the different parts of the system and allow the development, testing, and deployment of each part independently.
This is the core layer of the architecture, which contains the business logic and the use cases of the app. It defines the interactions between the different components of the system, but it does not contain any implementation details, such as how the data is stored or how it is displayed on the screen. The Domain layer communicates with the other layers through interfaces, which are defined in this layer.
This layer is responsible for presenting the data to the user and receiving user input. It is the intermediary between the Domain layer and the UI layer. The Presentation layer communicates with the Domain layer through the use of interactors, which are classes that implement the use cases defined in the Domain layer. The Presentation layer also contains the view models, which are responsible for transforming the data received from the Domain layer into a format that is suitable for display on the screen.
This layer contains the activities, fragments, and other UI components that make up the app's interface. The UI layer communicates with the Presentation layer through the use of the view models, which provide the data that is displayed on the screen.
This layer contains the components that are responsible for accessing and storing the data that is used by the app. This layer communicates with the Domain layer through the use of repositories, which provide a single point of access to the data, regardless of where the data is stored.
This layer contains the concrete implementations of the data sources, such as a database, a REST API, or a shared preference. The Data Source layer communicates with the Data layer through the use of the data sources, which provide the data to the repositories.
The Navigation layer is responsible for handling the navigation between the different screens in the app. It helps to decouple the navigation logic from the UI layer and makes it easier to manage the navigation flow within the app.
In summary, the different layers of Android Clean Architecture provide a clear separation between the different components of the app, making it easier to maintain and test the app. By following a clean architecture approach, you can ensure that your app is scalable, maintainable, and testable.
https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html