Terminology IFC / Building Designer

IFC Class	DataGroup Catalog Type Such as door, window, column, pump, fan, and light fixture for example.
IFC Type	DataGroup Catalog Item Such as SingleTimberDoorF60_3x7, SingleMetalDoorF60_3x7, DoubleTimberDoorF60_6x7, and DoubleMetalDoorF60_6x7 for example.

By default, delivered datasets support soft typing. Datagroup catalog items only define certain property values. And all of those property values can be redefined for that catalog item because the properties are Editable.