ntddk. h and wdf.h... libraries can tell me their usefulness in this code?

Question

#include <ntddk.h>
#include <wdf.h>
DRIVER_INITIALIZE DriverEntry;
EVT_WDF_DRIVER_DEVICE_ADD KmdfHelloWorldEvtDeviceAdd;

NTSTATUS DriverEntry(_In_ PDRIVER_OBJECT  DriverObject, _In_ PUNICODE_STRING RegistryPath)
{
    NTSTATUS status;
    WDF_DRIVER_CONFIG config;

    KdPrintEx(( DPFLTR_IHVDRIVER_ID, DPFLTR_INFO_LEVEL, "KmdfHelloWorld: DriverEntry\n" ));
    WDF_DRIVER_CONFIG_INIT(&config, KmdfHelloWorldEvtDeviceAdd);
    status = WdfDriverCreate(DriverObject, RegistryPath, WDF_NO_OBJECT_ATTRIBUTES, &config, WDF_NO_HANDLE);
    return status;
}

NTSTATUS KmdfHelloWorldEvtDeviceAdd(_In_ WDFDRIVER Driver, _Inout_ PWDFDEVICE_INIT DeviceInit)
{
    NTSTATUS status;
    WDFDEVICE hDevice;
    UNREFERENCED_PARAMETER(Driver);

    KdPrintEx(( DPFLTR_IHVDRIVER_ID, DPFLTR_INFO_LEVEL, "KmdfHelloWorld: KmdfHelloWorldEvtDeviceAdd\n" ));
    status = WdfDeviceCreate(&DeviceInit, WDF_NO_OBJECT_ATTRIBUTES, &hDevice);
    return status;
}

Answer 1

<ntddk.h> is the header of NT Driver Development Kit, the development kit of drivers (Windows) NT. It defines various types of data needed to write drivers in a Windows NT4 environment or higher (NTSTATUS, for example). A MSDN, however, recommends that the <wdm.h> instead - it is assumed that at least in cases that are not used <wdf.h>, down below.

<wdf.h> is the Windows Driver Frameworks, to new API of drivers from Microsoft. It provides other types of data, such as WDF_DRIVER_CONFIG and the WdfDriverCreate(), and is essentially the main API used in driver of his example.