An induction motor which connects with a 3-stage supply called 3-stage 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 frequent maintenance and we can not use DC motor in explosive and dirty three phase ac induction motor environment. But induction motors are cheaper,tough,lighter,smaller,require less maintenance and may use in filthy and explosive environment. Slide s is 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 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 electric motor is important
Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control