UML package
A package is used to represent the static structure of a system, particularly the types of objects handled in the system, their internal structure, and the relationships between them.
The package is an owner element. It provides a namespace for the elements that it consolidates.
The package allows you to classify elements referenced in a project. You can create sub-packages in a package to classify objects in finer detail, for example actors of a project.
Urgent purchase requests are provided to process purchase of spare parts and boat rental requests. In both of these cases, users are actors of the purchasing domain.
Class diagrams are used to graphically represent the elements of a package.
For more details on building a class diagram, see The Class Diagram.