Idle control servo motor/ also called a stepper motor.
It is controlled by the ecu and is used to vary the idle speed.
It can accurately vary the position of the throttle butterflies to provide cold start fast idle and prevent stalling when there is high electrical load etc.
It will, when working correctly,ensure correct idle speed when other variables come into play such as altitude,temp etc.
It’s basically a reversible motor,connected to a very fine screw thread with a plunger on it.
In one direction the plunger will push out,reversed it will retract.
From time to time it will need to be reinitialised using a diagnostic tool.
There may well be a method to initialise it without diag kit such as opening and closing the throttle with the ign on engine not running.
Hope this helps/ makes sense