stepper motor : an introduction

stepper motor is the motor moves in steps .

where the steps are being measured in angles viz. 1.5 degree or likewise.

it's of three types . but only two finds application  today are 1)PM-permanent magnet stepper motors
2) hybrid stepper motors

 PM steppers are of low cost ,low performance meaning that they produce much low torque.
Hybrid steppers are the best of three widely used today..-high cost,good performance.
for more details you must go through the following links:
1) http://en.wikipedia.org/wiki/Stepper_motor

2) stepper motor system basics

3)http://www.motiongroup.com/steppermotors_basics.shtml