The 'Package Diagram' supports one unique diagram construct: a 'Package.'
In the system model, a package is a construct that enables you to organize entities into groups. Packages define namespaces for packageable entities. Entities from one package can be imported and/or contained by another package. In the diagram, this construct is represented as a rounded box with a top tab (similar to the shape of a file folder) and contains the name of the 'Package' in the top section.