Three phase induction motors have a very simple construction made up of a stator covered with electromagnets, and a rotor composed of conductors shorted at each end, arranged as a “squirrel cage”. They work on the principle of induction in which a rotating electro-magnetic field it made through the use of a three-phase current at the stators electromagnets. Therefore induces a current in the rotor’s conductors, 
which in turns produces rotor’s magnetic field that tries to follow stator’s magnetic field, pulling the rotor into rotation.
Great things about AC Induction Motors are:
Induction motors are simple and rugged in structure. They are better quality and can operate in any environmental condition
Induction motors are cheaper in expense due to simple rotor construction, absence of brushes, commutators, and slide rings
They are maintenance free motors unlike dc motors due to the lack of brushes, commutators and slip rings
Induction motors could be operated in polluted and explosive environments as they don’t have brushes that may cause sparks
AC Induction motors are Asynchronous Machines and therefore the rotor will not turn at the specific same speed as the stator’s rotating magnetic field. Some difference in the rotor and stator quickness is necessary to be able to generate the induction in to the rotor. The difference between the two is called the slip. Slip must be kept within an optimal range to ensure that the motor to operate effectively. Roboteq AC Induction controllers can be configured to operate in one of three modes:
Scallar (or Volts per Hertz): an Open up loop mode in which a command causes a simultaneous, fixed-ratio Frequency and Voltage alter.
Controlled Slip: a Induction Motor Closed Loop speed where voltage and frequency are managed in order to keep slip inside a narrow range while operating at a preferred speed.
Field Oriented Control (Vector Drive): a Closed Loop Velocity and Torque control that functions by optimizing the rotating field of the stator vs. this of the induced field in the rotor.
Discover this video from Learning Engineering for a visual illustration about how AC Induction Motors are constructed and function.