Complex systems are typically made up of a large number of interacting components—people, ants, brain cells, startups—that together exhibit adaptive or emergent behavior without requiring a leader or central control. As a result, complex systems are more about the relationships and interactions among their components than about the components themselves. And these interactions give rise to unpredictable behavior. If a system surprises you, or has the potential to surprise you, it is likely complex. Software is complicated. Creating a software startup is complex. An airplane is complicated. What happens between the people on board is complex.
Aaron Dignan in Brave New Work