NLayer Architecture in abp

https://aspnetboilerplate.com/Pages/Documents/NLayer-Architecture

Introduction

The layering of an application's codebase is a widely accepted technique to help reduce complexity and to improve code reusability. To achieve a layered architecture, ASP.NET Boilerplate follows the principles of Domain Driven Design.

Domain Driven Design Layers

There are four fundamental layers in Domain Driven Design (DDD):

• Presentation Layer: Provides an interface to the user. Uses the Application Layer to achieve user interactions.
• Application Layer: Mediates between the Presentation and Domain Layers. Orchestrates business objects to perform specific application tasks.
• Domain Layer: Includes business objects and their rules. This is the heart of the application.
• Infrastructure Layer: Provides generic technical capabilities that support higher layers mostly using 3rd-party libraries.

https://abp.io/documents/abp/latest/Domain-Driven-Design

What is DDD?

ABP framework provides an infrastructure to make DDD based development easier to implement.

DDD is defined in the Wikipedia as below:

Domain-driven design (DDD) is an approach to software development for complex needs by connecting the implementation to an evolving model. The premise of domain-driven design is the following:

• Placing the project's primary focus on the core domain and domain logic;
• Basing complex designs on a model of the domain;
• Initiating a creative collaboration between technical and domain experts to iteratively refine a conceptual model that addresses particular domain problems.

Layers

ABP follows DDD principles and patterns to achieve a layered application model which consists of four fundamental layers:

• Presentation Layer: Provides an interface to the user. Uses the Application Layer to achieve user interactions.
• Application Layer: Mediates between the Presentation and Domain Layers. Orchestrates business objects to perform specific application tasks. Implements use cases as the application logic.
• Domain Layer: Includes business objects and their business rules. This is the heart of the application.
• Infrastructure Layer: Provides generic technical capabilities that support higher layers mostly using 3rd-party libraries.

Contents

• Domain Layer
  • Entities & Aggregate Roots
  • Value Objects
  • Repositories
  • Domain Services
  • Specifications
• Application Layer
  • Application Services
  • Data Transfer Objects (DTOs)
  • Unit of Work