What is the difference between the two phase stepping motor and the four-phase step motor?
The dual-polarity drive can drive a single polarity motor, but a unipolar drive cannot drive a bipolar motor. To put it bluntly, four phases of maeda draw two lines in the middle of the AB winding.
The same thing, only internal wiring is different! Two phase motors are connected by four lines, four phases are six lines, two polar motors, four phases a single polarity motor.
The volume of four phases is larger and costlier. But the Angle is small and the control precision is high. The two-phase step Angle is large and the control precision is not as good as four phases.