WASAPI, or Windows Audio Session API, is a Microsoft interface that allows applications to interact with audio devices on Windows operating systems. It provides low-latency audio playback and recording, making it suitable for professional audio applications and gaming. WASAPI supports both exclusive and shared modes, enabling developers to choose how their applications access audio hardware. In exclusive mode, an application can take full control of the audio device, bypassing the operating system's audio mixing. This results in higher audio quality and lower latency. In shared mode, multiple applications can use the audio device simultaneously, which is more convenient for general use but may introduce some latency.