This document provides an overview and introduction to domain-driven design (DDD). It discusses the core principles of DDD, including focusing on modeling the domain, capturing domain knowledge in software models, and structuring software around domain concepts. The document also summarizes some common DDD patterns and techniques for managing complexity, such as ubiquitous language, layered architecture, aggregates, entities, value objects, services, factories, and repositories. The overall goal of DDD is to build software that is closely aligned with the conceptual model of the problem domain.