The full form of VDC is Vehicle Dynamics Control.

In simple terms, Subaru Vehicle Dynamics Control (VDC) is a form of electronic stability control. This advanced active safety system utilizes a network of sensors to monitor wheel speed, steering wheel position, yaw rate and lateral acceleration. If the sensors detect that the vehicle is not moving in the intended direction, the system will take steps to try to correct the situation. Since most Subaru models are equipped with symmetrical full-time AWD, the VDC system relies on this first to maximize traction and restore vehicle stability at the first signs of trouble. If this doesn’t produce the desired results, VDC will then take corrective action by adjusting torque-split front to rear (CVT models only), applying the brakes to individual wheels, altering engine timing and reducing fuel flow to the engine .This combination of Subaru symmetrical full-time AWD and VDC produces superior levels of active safety with even more unique added benefits.

In three words, VDC prevents skids.  When you’re driving around a curve, you know where you want your car to go. Your Subaru does, too, because it has a host of sensors that monitor where your car is and where you’re pointing it.  If your wheels start to move laterally, sending your car for the ditch, VDC will reduce engine power and/or apply the brakes to slow down individual wheels, pulling your car back into your intended line through the curve.  First introduced as an option in 2001, it has been standard on every Subaru since 2009.