HOW TO USE FUNCTION SETPOSITION (MOTOR CONTROL)

[hmga33]

Hello.

Now, I'm interested in control the position of the motor.
I would like to know how the function setPosition is performed:
-it is possible without any hall sensor?
-it is possible to use one analog hall sensor (voltage proportional to angle) instead of three digital hall sensors.

I would like to know the meaning of the variable position, that is, this variable indicates how many degrees the motor rotates?