Context

Domains are the highest level of this pattern language. They correspond to the enterprise or business view of the problem space that used to be the starting point for analysis. However, rather than being bounded by the formal limits of an organization, domains are flexibly and practically defined.

For my purpose, they are an area of interest (a typical dictionary definition of domain) with the following:

• A shared vocabulary of business abstractions (events, concepts, and things)

• A common set of needs that can be addressed by a family of applications

Domains also provide the context and organizing structure for the models of those applications; the models that are used in guiding their design, implementation, and management.

A domain defines the context and environment for understanding the common needs that drive the development of a set of software products. It identifies the problems that are legitimate and that are solvable within the specific scope of those needs.

Domains are the starting point for serious modeling that will lead to real, substantial software. There are two types of domain that are of interest to a software developer:

• Business domains:

  Areas of interest to the business, containing fundamental business abstractions that are the ideas, the entities, and the events that package business services in a way that is meaningful to the business

• Technical domain:

  The infrastructure, technology vision, and technological constraints that must be respected