What are the advantages and disadvantages of stepper system (Stepper motor)

Stepper motor - DC current generates a magnetic field.It is constant current system. Torque drops off as a function of speed due to the number of rotor poles.

Advantages of Stepper motor

Simple design Simple control Excellent low speed torque Excellent low speed smoothness Lowe overall system cost

Disadvantages of Stepper motor

Torque decreases as speed increases Constant current regardless of requirement No method to overcome position loss