Phantom power is a method used to supply power to certain audio devices, like condenser microphones, through the same cable that carries the audio signal. This allows the microphone to operate without needing a separate power source, making it convenient for recording and live sound applications. Typically, phantom power is provided at a voltage of 48 volts, although some devices may use lower voltages. It is commonly supplied by mixing consoles or audio interfaces, ensuring that the microphone receives the necessary power while maintaining a clean audio signal.