You can place objects on other objects or in other objects. The difference between these two procedures is as follows: When placing an object on another object you specify that no implicit connection will be created between the objects. In contrast, when placing an object in another object you specify that an implicit connection is to be created between the objects.
You can place multiple objects of one type in an object at once. If you want to embed two objects at once and object 1 already has a connection to the enclosing object while object 2 has none, proceed as follows when creating connections:
Objects that were placed in other objects are also moved when the enclosing object is moved. If an enclosing object is selected, the embedded object is selected as well. This indicates clearly that an object is embedded in another object. In contrast, a non-embedded object is neither selected nor moved when the object on which it was placed is selected or moved.
You can drag an embedded object from an enclosing object to the model background. The connections linking the objects are then displayed.