You are probably referring to the steering. For many years power
steering was accomplished by assisting the steering effort with
hydraulic pressure. This hydraulic pressure is generated at the
hyraulic pump commonly referred to as the power steering
pump. Newer technology is to use an electric motor to provide
the steering effort assist. This electric motor is part of the
steering gear mechanism. The benefit of electric versus
hydraulic is that the engine does not have to constantly spin a
hydraulic pump and that saves energy and improves fuel
mileage. Electric is more efficient and hydraulic is a long proven
technology. I am not sure which one is better than the other.