Domain model

In domain-driven design, a domain model is a key artifact that captures the domain of a software system, its subdomains, and the relationships between the subdomains.

A domain model is a system of abstractions that describe all aspects of a domain, which itself consists of selected features of the real world context that are relevant to the software requirements. A model should contain just enough information to be a useful reference point when solving problems in that domain using software.

Models help us to deal with the [essential complexity] of software systems.