An induction electric motor or asynchronous motor can be an AC electric electric motor in which the electric current in the rotor had a need to create torque is obtained by electromagnetic induction from the magnetic field of the stator winding. … An induction motor’s rotor can be either wound type or squirrel-cage type.
Great things about AC Induction Motors are:
Induction motors are basic and rugged in construction. They are better quality and can operate in virtually any environmental condition
Induction motors are cheaper in cost due to simple rotor construction, lack of brushes, commutators, 
and slide rings
They are free of maintenance motors unlike dc motors due to the lack of brushes, commutators and slip rings
Induction motors can be operated in polluted and explosive environments as they don’t have brushes that may cause sparks
AC Induction motors are Asynchronous Devices and therefore the rotor will not turn at the specific same speed since the stator’s rotating magnetic field. Some difference in the rotor and stator swiftness is necessary in order to create the induction in to the rotor. The difference between your two is called the slip. Slip must be kept within an optimal range in order for the motor to use efficiently. Roboteq AC Induction controllers can be configured to operate in one of three modes:
Scallar (or Volts per Hertz): an Open loop mode in which a order causes a simultaneous, fixed-ratio ac motor Frequency and Voltage change.
Controlled Slip: a Closed Loop speed where voltage and frequency are managed in order to keep slip within a narrow range while operating at a desired speed.
Field Oriented Control (Vector Drive): a Closed Loop Speed and Torque control that works by optimizing the rotating field of the stator vs. this of the induced field in the rotor.
See this video from Learning Engineering for a visual illustration on how AC Induction Motors are constructed and work.