Configurable Joint - What does Position Spring and Damper mean?

The position spring and damper affect the force which tries to keep your rigidbody pinned to a certain spot. This spot could be another rigidbody (if you have set the connected body to another rigidbody), or a world location (if you have not).

The spring value affects the strength of the force applied proportional to how far the object is away from its intended spot - so this is basically how strong the spring is.

The damper value affects the momentum of the spring, which is basically its dendency to overshoot and oscillate back and forth. A higher value for the damper will make the spring come to rest much faster, whereas a low damper value will allow it to twang back and forth for a longer time before eventually coming to rest.

In this way, the 'damper' value acts like a shock absorber, taking force out of the springs movement.

However, you mentioned "that perfect effect", but you haven't actually described what you're trying to do! so while this information about joints might be useful, I can't help you any further with the effect you're trying to achieve!