Normally the word “chaos” evokes a lack of order: a hectic day, a teenager’s bedroom, tax season. And the physical understanding of chaos is not far off. It’s something that is extremely difficult to predict, like the weather. Chaos allows a small blip (the flutter of a butterfly wing) to grow into a big consequence (a typhoon halfway across the world), which explains why weather forecasts more than a few days into the future can be unreliable. Individual air molecules, which are constantly bouncing around, are also chaotic—it’s nearly impossible to pin down where any single molecule might be at any given moment.
Source:
https://phys.org/news/2021-01-chaos-tendency-thermal-equilibrium-fundamental.html