Often shortened to just ASM, this computer-controlled system assists the driver in situations where the vehicle becomes difficult to control, or when there is an unexpected loss in traction due to environment conditions or tire limitations.
There are a number of different types of stability control systems, but the aim is to do as the name suggests: maintain an active level of stability for the driver.
It differs from traction control by attempting to keep the driver's intentions in mind (via a computer system) by taking the throttle position and steering into account. Instead of simply trying to keep the wheels from spinning, it considers which way the driver intends to go, and how quickly, and adjusts accordingly.
Although Active Stability Management differs from traction control, it is often used interchangably when marketed by automotive manufacturers.