You might have heard this metaphor & it seems weird too, that how can a butterfly cause a tornado.
The butterfly effect simply stated is a phenomenon wherein a small change in starting conditions can lead to vastly different outcomes.
Discovered by an MIT mathematician, who was calculating weather patterns by running simulations.
In the first simulation, he put in the data to six decimal places. Before running the second simulation he thought that those tiny fractions of a degree wouldn't matter, so he only used three decimal places & got a drastically different result this time.
It was unrecognisable!
That's the butterfly effect -- which does have a scientific name: "sensitive dependence on initial conditions." and that's when the butterfly effect got formulated.
During that time mathematicians thought, if you changed a little at the start, it would only affect a little at the end. Though, It was logical, but "systems" don't behave that way!
"The Butterfly Effect" is simply meant to demonstrate that little events which may feel insignificant to us can lead to significant results over time.
Each event can be explained by finding the small reasons that caused it. What we can learn from butterfly effect is that however small or insignificant one's action may seem, they can always result into something huge.
It also leads us to the importance of hard work which not always means moving mountains but just by starting with small steps of improvement.