Interfaces have names.
The main DirectDraw interface is called IDirectDraw . You get a IDirectDraw interface pointer by calling DirectDrawCreate as shown in the following code sample. The IDirectDraw interface was introduced with DirectX 1. Two more DirectDraw interfaces are available which are extensions of the IDirectDraw interface - they add some new functions but change none of the older functions. QueryInterface is a method in the IUnknown interface that all COM interfaces inherit from.