Maybe the reference is about the XDDM/XPDM vs. WDDM driver models, the latter has a kernel-mode and a user-mode portion: https://learn.microsoft.com/en-us/windo

Maybe the reference is about the XDDM/XPDM vs. WDDM driver models, the latter has a kernel-mode and a user-mode portion: https://learn.microsoft.com/en-us/windows-hardware/drivers/display/windows-vista-and-later-display-driver-model-architecture https://learn.microsoft.com/en-us/windows-hardware/drivers/d...