https://docs.abp.io/en/abp/master/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 把…编成管弦乐曲；（美）精心安排；把…协调地结合起来 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

Domain Driven Design

原文：https://www.cnblogs.com/chucklu/p/13049217.html