This light comes on briefly when the ignition is turned on, as a check to show that it is working. Then it should go out.
If it stays on, or comes on while the vehicle is being driven, a chime will sound and there may be a problem with the charging system. It could indicate that the vehicle has a loose accessory belt or another electrical problem. Have it checked right away. Driving while this light is on could drain the battery and result in the engine suddenly stopping.
If the vehicle must be driven a short distance with the light on, be certain to turn off all unnecessary electrical loads, such as the radio, heater fan, air conditioning fan, and heated seats.