Rotate into direction of another object ?

Scripting
1

Hi Guys
How to make one object rotate into direction of another object, and control his speed.

    public Transform ManFace;
    public float f_RotSpeed=3.0f, f_MoveSpeed = 2.0f;
    public float rots; // manFace rotate y value

    // Use this for initialization

    // Update is called once per frame
    void Update () {
        /* object rotate speed*/
      //  rots = ManFace.transform.rotation.y;
      //  transform.Rotate(0.0f,rots,0.0f); // it gives me wrong value ?
       
        /* object moves speed*/
        transform.position += transform.forward * f_MoveSpeed * Time.deltaTime;

    }
2

use Quaternion.LookRotation(), pass the direction from the object’s postion to the target’s postion, and set that quaternion result to the objects rotation