A "homoploar" motor is a motor that works with the need for a commutator. The commutator is used to switch polarity between pairs of poles of a motor. This motor has one pole, It the explanation uses the right hand rule where the thumb points in the direction of the current, the fingers are in the direction of the the b-field, and the palm is the push or the applied force. Current is defined as the flow of positive charge because positive charges flow from high energy to low.)