The BtCap WDM Audio Capture driver is a Windows driver associated with Bluetooth audio capture devices, specifically used for capturing audio streams from Bluetooth-enabled devices. It is commonly used in setups where Bluetooth microphones, headsets, or other Bluetooth audio devices are being used to input or output audio to/from a PC. This driver is a part of the Bluetooth audio capture functionality, and it's typically installed when you have Bluetooth audio devices connected to your PC.

WDM (Windows Driver Model) refers to the architecture that Windows uses for its drivers, ensuring that they work efficiently across various versions of Windows. The BtCap driver helps handle the communication between Bluetooth audio hardware and the operating system.