An induction motor or 3 stage induction motor can be 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 electric motor which connects with a 3-phase supply called 3-phase induction motor. Example fans,blowers, cranes,traction .It is a ac electric motor. The main drawback of DC motors is the presence of commutator and brushes, which require Three Phase Motor frequent maintenance and we can not use DC electric motor in explosive and dirty environment. But induction motors are cheaper,durable,lighter,smaller,require much less maintenance and may use in dirty and explosive environment. Slide s is the imp factor 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 velocity control technique of induction electric motor is important
Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control