The Arduino's output pins can only handle about 20mA continuously, not enough to drive a motor, so, yes you do need a driver to suit your motor. There are different types of steppers so we can't say which driver without knowing which motor.
The Arduino's output pins can only handle about 20mA continuously, not enough to drive a motor, so, yes you do need a driver to suit your motor. There are different types of steppers so we can't say which driver without knowing which motor.