Domain's notions
Concepts
Domain concept literally refers to an abstract idea which is meaningful
in the domain in question.
There are 3 different types of domain
concepts : the domain entity, the domain action and the domain quality.
Instances
They are examples of a particular domain concept.
For instance, if "Window" is a domain concept, "that window" is a domain
instance of it.
If "push" is a domain concept, "he pushes the bell" is a domain instance
of "push".
Corresponding to the three concept categories, there are three classes
of domain instances, namely, entity instance, action instance and quality
instance.
Two domain instances will be judged as identical if they share the
same name and belong to the same concept.
Relations
They describe relationships among domain entities and domain actions.
There are two predefined domain
relations : entity-centered relations, action-centered relations.