Transformers may have mulitple windings, but must have at least two. The Primary is the higher voltage, often denoted H. The secondary is the lower voltage (higher amperage) winding, often denoted X....
A 'compund wound' dc generator has shunt winding and a series winding. The shunt winding has a high resistance, and draws only a small current from the armature, but as it has many turns of wire on...
starting winding is used only at the time of starting while running winding always remain connected to the supply hence in order to have high efficiency running winding has least resistance.