A complex system is a class of interdependent entities, components, or parts, which interact dynamically and nonlinearly to produce emergent, unpredictable behaviour arising from the whole. This behaviour cannot be determined from the behaviour of its constituent elements, but is instead intrinsic to the system as a whole. Complex systems contain both order and chaos, feedback loops and other nonlinear dynamics, which can often lead to the generation of novel outcomes. These systems can be studied and understood through the application of tools and theories from related scientific, computer and engineering disciplines.

See also: emergence, evolutionary computing, agent-based modeling, antifragile, edge of chaos