non physics GO slowly stop when near target location.

I have a GameObject with smoothfollow script attached to it. My goal is that when this GO is close to the target(such as within 10 meters range), it would smoothly slow down to stop, without actually reaching the pivot point of target. I have tried to setup different bool and conditions, but result in jagging movement. so how will you do it? on a side note what does the "velocity" inside Mathf.SmoothDamp do?

     public float smoothTime;
     public GameObject target
     private Vector3 velocity;
     
 
     void Start () 
     {
         smoothTime = 0.3f;        
     }
     void Update ()
     {
         transform.position = new Vector3(Mathf.SmoothDamp(transform.position.x, target.transform.position.x, ref velocity.x, smoothTime),
                                       transform.position.y, 
                                       Mathf.SmoothDamp(transform.position.z, target.transform.position.z, ref velocity.z, smoothTime));
     }