The assembly that implements the domain of your
application, i.e. contains your subclasses of
DomainObject (or, BindableDomainObject).
Such subclasses are called domain object classes
or domain classes.
The domain assembly can be inspected by dbschema.exe
to derive a database schema for persisting instances
of your domain classes.
The domain assembly can be inspected by uigen.exe
to discover your domain model (http://en.wikipedia.org/wiki/Domain_model)
and derive a functional web application from it.