A goal is an object that particles follow or move towards. You can use goals to give trailing particles a flowing motion that’s hard to generate with other animation techniques. The trailing particles move as if connected to the goal by invisible springs. In the context of goals, soft bodies are considered particles.
A goal can be any object except a curve on surface. The movement or motion of the trailing object depends on the type of goal object and the number of goal objects connected to the trailing object.