A system is a group of parts so linked together by interactions that the group functions as a whole. All of nature consists of systems within systems. The properties of the whole system are more than the simple addition of the properties of the parts and there is a general tendency for systems to combine to form more complex systems with more complex behavior.
Self-organizing systems are systems that spontaneously form from the association of compatible parts. The forms and functions of the systems are new and arise from the relationships among parts.
The ability of systems to self-organize and spontaneously develop new unpredictable behaviors or structures brings novelty into the universe.