The Kinect for Windows SDK works as an interface between the Kinect device and your application. When you need to access the sensor, the application sends an API call to the driver. The Kinect driver controls access to sensor data. To take a granular look inside the application interfacing with the sensor, refer to the following diagram:
The installed drivers for the sensors sit with the components of system device drivers and can talk to each other. The drivers help to stream the video and audio data from the sensors and return it to the application. These drivers help to detect the Kinect microphone array as a default audio device and also help the array to interact with the Windows default speech recognition engine. Another part of the Kinect device driver controls the USB hubs on the connected sensor as well.