e·mer·gence
/əˈmərjəns/
“In philosophy, systems theory, science, and art, emergence occurs when a complex entity has properties or behaviors that its parts do not have on their own, and emerge only when they interact in a wider whole.” - Wikipedia
It almost sounds funny to say that the basis of the human experience of reality, and likely consciousness itself, stems from the concept of emergence. The core principles of which seem to be attached to nearly all aspects of science and philosophy.
Lot’s of simple small things, acting together, tend to become big complex things distinctly different and containing different properties than the sum of their parts. So long as those base things act in concert within the bounds of some variable ruleset, the resulting systems can vary widely in structure, properties, and complexity. Life itself arising from nonbiological base chemistry is an example of such complexity. Emergence in this way can cascade forwards and backwards onto itself. Think about it like this (mind the gaps):
Atoms > Molecules > Elements > Chemicals > Cells > Oranisms > Species > Humans > Societies > ?
Each step on this ladder has nearly infinite levels of complexity individually, let alone when they are additive. This type of chain can be used to represent all things in our experience of the universe.
The same can happen in reverse by the way, where by simplicity emerges from complexity. Temperature, or our measure of perceived hotness and coldness is a simple property emerging from rules followed by molecules in response to arrangement and energy at scale.
Water
A (near) perfect example of emergence in physics. It is chemically easy to describe, "Water" (H2o) arising by the bonding of 2-Hydrogen and 1-Oxygen molecules. Depending its interactions with other factors (namely energy and arrangement) within the confines of reality, it can take on/move between multiple states of “being” such as Ice or Steam; both of which have their own unique properties but are fundamentally still H2o.
https://www.nature.com/articles/s41598-023-50651-x https://www.templeton.org/news/what-is-emergence