Chaos theory is a mathematical concept that is defined as “the study of apparently random or unpredictable behavior in systems governed by deterministic laws.” One principle of chaos theory is the butterfly effect, defined as “the sensitive dependence on initial conditions in which a small change in one state of a deterministic nonlinear system can result in large differences in a later state.”
To put it in much simpler terms, the butterfly effect argues that small and seemingly unrelated moments will have a significant effect on much larger happenings down the line — the most common example being given is one of a butterfly apparently causing a change in weather patterns as a result of it flapping its wings.