The difference between stepper motor and servo motor:

Stepper motor: moves to the step, having a fixed number of steps per revolution. Thus, it can be controlled with jumps of step size in any number of revolutions.

It can be one-way or two-way. The degree of each step is exactly the same.

Hold the torque high (relative), even if the coil power, hold the torque will still be reduced.

Servo motors (especially amateur servo motors) : Move smoothly from “stationary position” to “target position” and hold this position until the control signal changes. There are no steps.

It’s bidirectional in nature, but it’s essentially a limited range of deviations. Pure analog control is an option. But it doesn’t have to be linear.

Unlike stepper motors, maintaining torque depends on whether the motor is energized.

Typical amateur steering gear will change from -90 degrees to +90 degrees, or from -170 degrees to +170 degrees. The multi-turn server changes the x-rotation deviation from the x-rest direction to the x-rotation in the opposite direction.