you would think of a sentence with words or a series of symbols and merely by changing the positions of the symbols or choosing different combinations of these words we can create extremely complex structures.
Unsurprisingly, i found this explanation easier to understand.
Nature works the same way. You and I are made of atoms, just like the sun, but it's the arrangement which makes the difference. At the base layer of reality is speculated to be simple 2d strings.
Composability in practice, composable cellular automata is an area to research: