The Class group can be used for Package diagrams, Class diagrams and Object diagrams: those that usually display elements concerned with the logical structure of the system. These include Objects, Classes and Interfaces. Logical models can include domain models (high level business driven object model) to strict development Class models (define inheritance, attributes, operations).
The Class group is used for creating Class models and database models. Class modeling is done using the Class and Interface elements, as well as occasional use of the Object element to model Class instances. You can add Association or Aggregation relationships. See the Class Model for an example of this.
Use the Table element to insert a stereotyped Class for use in database modeling. See the Data Modeling topic for more details.
To add an element to the current diagram, click on the required icon and drag it into position on the diagram. Set an element name and other properties as prompted.
To add a relationship, click on the required icon, click on the start element in the diagram and drag to the end element.