Stepper Motor or Servo?

Good morning friends!

I'm relatively new with programming, so I have a lot of queations.

I want to turn a polarisation mount with a gearwheel and a servo or stepper motor.

The stepper/servo must rotate more than one time, so i don't know: Can a servo rotate many times or only between the ankle 0° to 180°?

If I would use a stepper I need the option to save the actual position or an option to get the stepper back to 0°.

Can you help me?

Some servos can turn more than 180 degrees. Look for sail winch servos. Those servos are still limited in terms of how many turns they can do. If you use a stepper, you will need a way to "home" the stepper at power up (or reset). A common way is with a switch or photo sensor that is triggered at the 0 degrees position. Step the motor and check the sensor, rinse and repeat till the sensor changes state. You are then at 0 degrees. As you move the stepper from 0, count the steps and you know where you are. To return to 0, reverse the number of counted steps or re-home.
An introduction to stepper motors.

Helped a lot, thank you groundFungus.