You can only create complex types in a model targeted with XSD.
A complex type is a data type definition used to define attributes and child elements of a parent element. It is a template for a data type definition that can be reused and derived by extension or restriction.
A complex type has:
a global scope when it has no parent element in the diagram and when it is directly linked to the <schema> tag. It can then be reused or derived, by extension or restriction, in other parts of the schema.
a local scope when integrated into an <element> tag. It applies only to its containing element.
The following illustration shows a diagram containing a complex type:
In the example above, HighDefinition is a global complex type, reused as data type for the deluxeTV element.
The generated schema is the following: