twice resolution (full stepping)
by alternately energizing one winding are then two , the motor moves through only 0.9 degrees at each step and the number of step per revolution will be doubied (400steps). this is called ''half-stepping'' this mode results in much better smoothness at low speed.
assuming the windings currents are the same, this will cause greater torque to be produced when there are two winding energized. alternate steps will by using a higher current level when there is only one winding energized (half step current profiled)