Definition
Complexity is a system property arising from interactions, interdependencies and changing behaviour among elements that make the behaviour of the whole difficult to predict from the parts alone.
Human Explanation
When elements influence and adapt to one another, the same action may produce different results depending on context and timing.
Why it Matters
In complex systems, apparently simple interventions can create delayed, indirect or unexpected consequences.
Conceptual Boundary
Complexity is not the same as complication. A complicated system may have many parts yet remain predictable when understood; a complex system can generate changing or emergent behaviour through interactions.
Practical Perspective
Complexity calls for clear boundaries, monitoring, feedback and decisions that can be adjusted as evidence develops. It is not an excuse to avoid action, but a reason to avoid false certainty.