что такое easing и springing

[Dear.D]

Что такое скорость и ускорение - понятно, а что такое easing и springing, не врублюсь. Похоже на авторские примочки.

The difference between easing and springing is in what aspect of the motion is proportional. In easing, velocity is proportional to the distance; the further away from the target, the faster the object moves. As it gets very, very close to the object, it’s hardly moving at all.

In springing, acceleration is proportional to the distance. If the object is far away from the target, a whole lot of acceleration is applied, increasing the velocity quickly. As the object gets closer to its target, less acceleration is applied, but it’s still accelerating! It flies right past the target, and then
acceleration pulls it back. Eventually, friction causes it to settle down.

Может кто поможет понять.