In a cloud of molecules some collide, and perhaps interact. Their trajectories are impossible to calculate, and you can't say which oxygen will combine with which hydrogen. It may take a lot of bouncing around to get all the bits combined. But looking at the bigger picture, you can say the oxygen and hydrogen reliably burn to form water.
There are so many molecules in a single cc of air that all the computers on Earth can't predict the trajectories in detail. It looks wild and chaotic on the microscopic scale, but on our scale PV=nRT is a very simple and useful equation.
Inside an amoeba complicated molecules move this way and that with no obvious pattern, but widen the view a bit and you see them breaking down the lump the amoeba engulfed. Widen the view some more and you see an active creature moving about and eating and reproducing.
The plant scatters seeds randomly, and hundreds of other plants compete for the same space. A cow mashes some into the mud. A falling tree obliterates another region. But the big picture shows a green meadow--with its own kind of order. And it's a robust order--or antifragile, if you prefer.
Economies seem to work similarly: disorder at one level, smoothed out to much more orderly at larger scales.
Sometimes my life seems to consist of reacting to one chaotic crisis after another, but at the end of the year it has had a flavor different from somebody else's reacting to chaotic crises.
A crystal is very orderly. Kind of limited, though. Chaos--the building material for order?