When selecting a motor, there are a few major decisions to make, and one of the biggest is whether to choose a one or a three phase motor. The three-phase models feature three hot leads, which means that there is less time between peaks in the current. Each leg that is carrying power is at a peak for one third of the time while the other two rotate through.
This cycle allows the motor to run more smoothly than one-phase units. It also creates a magnetic field that rotates in a specific direction, allowing for a more simplistic motor design. Generally three phase motors are more compact and cheaper than their one-phase counterparts as well.