Synchronous motor

How works a three-phase synchronous motor?

The following video describes the functioning of a 3 phase synchronous motor. From the content:
0:00 Introduction
0:31 Structure of the synchron motor
0:50 How torque is built
1:14 How make this motor self-starting
1:50 Synchronous motor in operation
2:11 Nameplate
2:43 Applications