You may have detected a cause and effect relationship among the elements of motion we have been studying under the heading of kinematics . Consider a particle at rest in our reference frame. It can't undergo a displacement, that is change position without getting a velocity. It can't change its velocity from zero without getting an acceleration.
Acceleration seems to be at the root of motion as far as kinematics is concerned.
Now we need to peel back the next layer and look at the cause of acceleration. That takes us out of the realm of kinematics into the next level of mechanics, called dynamics . A fundamental concept in dynamics is the dynamical system. Since dynamics is the study of motion and forces , things that move or things under the influence of forces or both are called dynamical systems. For example a satellite in orbit around the Earth is a dynamical system.