An induction motor or 3 phase induction motor can be an AC 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 which connects with a 3-phase supply called 3-stage induction motor. Example supporters,blowers, cranes,traction .It is a ac engine. The primary drawback of DC motors is the existence of commutator and brushes, which require frequent maintenance and we can not use DC motor in explosive and filthy environment. But induction motors are cheaper,rugged,lighter,smaller,require less maintenance and can use in 
filthy and explosive environment. Slip s may be the imp element in this kind of motor.
There are 2 types of IM.
Squirrel cage IM
Slip ring IM
There are many starting and braking condition.
Important starting methods are
Star-delta Three Phase Motor starter
Auto transformer starter
Ac voltage controller starter
Rotor resistance starter
Important braking methods are
Regenerative braking
Plugging or invert voltage braking
Dynamic braking
But one thing quickness control technique of induction motor is important
Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control