1. Abstract VB-Cable is a virtual audio device driver for Microsoft Windows that creates a "bridge" between software applications. It allows users to route audio output from one program to the input of another, bypassing physical hardware connections. This paper explains the architecture, installation, use cases, and limitations of VB-Cable, providing a practical guide for audio engineers, streamers, and general users. 2. Introduction In a typical Windows environment, audio flows from an application (e.g., Spotify) to a physical output (e.g., speakers). Simultaneously, a microphone sends audio to an application (e.g., Discord). However, routing audio between applications—such as playing a game’s sound into a voice chat as background music—requires a virtual connection.