There exists some confusion about the relationship of chaos and complexity.
Chaos can be more or less strictly defined.
A reasonably strict definition is that chaos deals with deterministic systems whose trajectories diverge exponentially over time. This property is expected to be found in the behavior of complex systems. However, how it can be related to various properties of complex systems continues to be an important area of research. Using these models some characteristic behaviors of their dynamics can be found. Complex systems do not necessarily have a natural representation of this form, or these behaviors.