The stepper motor rotates by a specific amount of steps per whole rotation. Depending on use context, different motors provides different amount of steps per rotation, varying from 12-200 steps. The stepper motor enables a controlled amount of movement as result of the instructed amount of steps it receives, and is therefore used in contexts that require traveling to specific positions, such as printers. The stepper motor requires more specific control to function, but can be handled with an Arduino library.

Links:

Setup guide with Arduino library