An induction electric motor or 3 phase induction motor is an AC electric Three Phase Motor engine in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding
An induction electric motor which 
connects with a 3-phase supply called 3-stage induction motor. Example supporters,blowers, cranes,traction .It really is a ac motor. The primary drawback of DC motors may be the presence of commutator and brushes, which require regular maintenance and we can not use DC engine in explosive and dirty environment. But induction motors are cheaper,rugged,lighter,smaller,require less maintenance and will use in filthy and explosive environment. Slip s may be the imp factor in this kind of motor.
There are 2 types of IM.
Squirrel cage IM
Slip ring IM
There are various starting and braking condition.
Important starting methods are
Star-delta 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 swiftness control technique of induction engine is important
Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control