How to Draw a UML Association Class
An association class, which is essentially a class attached to an association, is used to model an association as a UML class. It has its own name, attributes operations, just like any other ordinary class. However, it is described by additional attributes which does not belong to the objects involved in the association. For example, an Enrollment class is added to hold the attribute year between Student class and Course class, but it does not belong to either Student class or Course class.
