stereotype a way of categorizing a model element by its characteristics, indicated by guillemots (>)
persistent class an class whose objects exist after a system is shut down (data remembered)
entity class a design identifier for a problem domain class (usually persistent)
boundary class or view class a class that exists on a system’s automation boundary, such as an input window form or Web page
control class a class that mediates between boundary classes and entity classes, acting as a switchboard between the view layer and domain layer
data access class a class that is used to retrieve data from and send data to a database