An induction motor or asynchronous motor is an AC electric electric motor in which the electric current in the rotor needed 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 structure. They are better quality and 
can operate in any environmental condition
Induction motors are cheaper in cost because of simple rotor ac motor construction, lack of brushes, commutators, and slip rings
They are free of maintenance motors unlike dc motors because of the lack of brushes, commutators and slip rings
Induction motors could be operated in polluted and explosive conditions as they don’t have brushes which can cause sparks
AC Induction motors are Asynchronous Devices meaning that the rotor does not convert at the specific same speed as the stator’s rotating magnetic field. Some difference in the rotor and stator swiftness is necessary to be able to create the induction into 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 operate efficiently. Roboteq AC Induction controllers could be configured to operate in one of three modes:
Scallar (or Volts per Hertz): an Open up loop mode where a order causes a simultaneous, fixed-ratio Frequency and Voltage change.
Controlled Slip: a Shut Loop speed where voltage and frequency are managed to keep slip within a narrow range while working 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.
Observe this video from Learning Engineering for a visual illustration on how AC Induction Motors are constructed and work.