WHAT’S THE DIFFERENCE??
AWD = A Wheel Drive.
4WS?? Do you mean 4wd???
4wd is 4 wheel drive.
There are several differences depending on what system you’re talking about. They’re NOT all the same. Basically AWD will have at least 1 wheel driving the vehicle at all times. If that wheel begins to slip then one of the other 4 wheels kicks in. This happens instantaneously. With a 4wd system…there are at least 2 wheels driving the vehicle at all times…one in the front axle and one in the rear.4wd is much much better for deep snow or mud or off-roading.
4WS = 4 wheel steering. Very rare feature, the Mitsubishi 3000 GT VR4 had it, Some older Preludes had it, and GM offered for a year or two on some of it’s trucks a few years back. As you might suspect 4 wheel steering means that all four wheels steer the vehicle. Unfortunately it’s a jolly expensive and complicated feature, so it’ not widely seen.
Your answer(1 wheel turning) on AWD is only correct on systems that sense slip and activate the opposing axle to turn. However there are many AWD systems on real SUVs(Land Rover, Jeep) and cars(Subaru, Audi) that use a typical 50/50 torque split and always have a wheel turning front or rear.
No blanket answer even on what is better, it all depends in what circumstance and make/model. Research is the key.