The Object group is used to create Object diagrams.
Object diagrams reflect multiplicity and the roles instantiated Classes could serve. They are useful in creating different cases in which relationships and Classes are applied.
The user is called an Actor and is drawn as a stick figure, although the user could be another computer system or similar.
An Object is an instance of a Class.
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, then click on the start element in the diagram and drag to the end element.