A stepper motor needs a specialised stepper motor driver. Stepper motors work in a very different way to DC motors. Stepper motors move one step for every pulse. The pulses are usually very short and the speed is controlled by varying the interval between pulses.These links may helpStepper Motor BasicsSimple Stepper CodeDC motors need a h-bridge motor driver (assuming you need to be able to control the direction). The h-bridge by itself just acts as a switch that is controlled by the Arduino. If you want to control the motor speed you do that using PWM (analogWrite() ) which generates a series of pulses with the width varying to control how much energy is passed to the motor. When the pulses are narrow the motor is only getting power for a small part of the PWM cycle. and the average energy passed to the motor is low. The pulse frequency is completely unrelated to the speed of the motor.A servo (meaning a hobby servo) has its electronic control inside the box so the Arduino just needs to send it a signal that indicates the position the servo arm should move to. Unfortunately the term PWM is also used for the signal that controls a servo although the way it is used is very different from the PWM that controls a DC motor. In the case of a servo the width of the pulse (between about 400 and 2400 microsecs) define the angle of the servo arm - roughly between 0 and 180 degrees, but that varies a bit with different servos....R
Ah, that makes more sense. Thank you for clarifying. I also added an edit to my post above regarding your tutorial(s). I would like to see more if they are available.