If your vehicle has the Traction Control System (TCS), this light will come on when the system is limiting wheel spin.
You may feel or hear the system working, but this is normal. The roads may be slippery if this light comes on. Adjust your driving accordingly.
The light will stay on for a few seconds after the system stops limiting wheel spin. This light should also come on for a few seconds when you start your vehicle. If it does not, have your vehicle serviced.
The low traction light also comes on briefly when you turn the ignition key to "RUN". If the light doesn't come on then, have it fixed so it will be there to tell you when the traction control system is active.