Architecture Styles
Manga uses ideas from popular architectural styles. They Ports and Adapters are the simplest one followed by the others, they complement each other and aim a software made by use cases decoupled from technology implementation details.
The general idea behind Hexagonal architecture style is that the dependencies (Adapters) required by the software to run are used behind an interface (Port).
The software is divided into Application and Infrastructure in which the adapters are interchangeable components developed and tested in isolation. The Application is loosely coupled to the Adapters and their implementation details.
Interfaces like ICustomerRepository, IOutputPort and IUnitOfWork are ports required by the application.
The interface implementations, they are specific to a technology and bring external capabilities. For instance the CustomerRepository inside the EntityFrameworkDataAccess folder provides capabilities to consume an SQL Server database.
Primary Actors are usually the user interface or the Test Suit.
The Secondary Actors are usually Databases, Cloud Services or other systems.
Very similar to Ports and Adapters, I would add that data objects cross boundaries as simple data structures. For instance, when the controller execute an use case it passes and immutable Input message. When the use cases calls an Presenter it gives a Output message (Data Transfer Objects if you like).
An application architecture implementation guided by tests cases.