An induction electric motor or 3 phase induction motor can be an AC electric motor in which the electric energy in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding
An induction engine which connects with a 3-phase supply called 3-phase induction motor. Example followers,blowers, cranes,traction .It 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 motor in explosive and filthy environment. But induction motors are cheaper,durable,lighter,smaller,require much less maintenance and can use in dirty and explosive environment. Slide 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 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 reverse voltage braking
Dynamic braking
But one thing speed control technique of induction motor is important
Pole Three Phase Motor changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance 
control