All you need to know is about an AC indusction motor and a universal (DC or AC) motor.
http://en.wikipedia.org/wiki/Induction_motor
http://en.wikipedia.org/wiki/Induction_motor
From HSC Online: " * There are two main types of electric motors that run on AC: universal motors and induction motors. Universal motors can run on either AC or DC and are essentially similar in construction to a DC motor Selecting this link will take you to an external site.
* An induction motor consists of a stator and a rotor. The stator consists of a series of wire coils wound on soft iron cores that surround the rotor. These are connected to the external power supply in such a way that they produce a magnetic field whose polarity rotates at constant speed in one direction. This is achieved in a three-phase induction motor by connecting consecutive coils in opposing pairs to the three phases of the power supply. Many single-phase induction motors use capacitors to simulate the three-phase effect.
* The rotor consists of coils wound on a laminated iron armature mounted on an axle. The rotor coils are not connected to the external power supply, and an induction motor has neither commutator nor brushes. An induction motor is so named because eddy currents are induced in the rotor coils by the rotating magnetic field of the stator. The eddy currents produce magnetic fields which interact with the rotating field of the stator to exert a torque on the rotor in the direction of rotation of the stator field.
* The rotor coils are often simplified to single copper bars capable of carrying a large current, imbedded in the surface of the armature. The bars are connected at the ends by a ring or disc of copper which allows current to flow in a loop between opposite bars. This physical arrangement is referred to as a squirrel cage because it resembles an exercise wheel for small mammals.
A Squirrel Cage induction rotor
* An induction motor has a fixed maximum speed. The magnetic field of the stator rotates at the frequency of the AC supply. In Australia, induction motors spin at about 3000 revolutions per minute (50 Hz x 60 seconds) without a load, but the speed of the rotor slips behind that of the field as a load is applied. "
http://www.hsc.csu.edu.au/physics/core/motors/2698/Phy935net.htm#net1
