An induction electric motor or 3 stage induction motor is an AC electric engine in which the electric current in the rotor had a need to generate 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-phase induction motor. 
Example enthusiasts,blowers, cranes,traction .It really is a ac engine. The primary drawback of DC motors is the presence of commutator and brushes, which require frequent maintenance and we can not use DC engine in Three Phase Motor explosive and filthy environment. But induction motors are cheaper,durable,lighter,smaller,require much less maintenance and can use in dirty and explosive environment. Slip s may be the imp element in this type of motor.
There are 2 types of IM.
Squirrel cage IM
Slip ring IM
There are numerous 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 acceleration control technique of induction engine is important
Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control