Emergence is one of the most interesting components of complex systems. The term complex systems can be used to describe entities that work together to form bigger and more complex entities (or systems). The entire universe is made up of these complex systems. A cell is a complex system. Cells are nested within another complex system, your organs. Those work together to form yet another complex system, your body. You also have your family as a complex system. Your neighborhood, community, city, country, and so forth. And those are just basic societal systems.
The point is that complex systems exist all around us. We participate in and feel their effects all day long without even realizing it.
So when does emergence occur? It occurs when an entity displays properties that its parts do not have on their own. An added layer of complexity emerges from coordinated efforts of its components. A basic example would be a balloon and helium. Without helium a balloon just sits there lifeless. And without a container, helium would just instantly dissolve into the air. But when you combine the two something happens: the balloon floats. This is emergence. It describes a sort of symbiotic relationship, from which all parties will ideally benefit. In other words, the whole is greater than the sum of its parts. This is the beauty of complex systems. Something new (and often times valuable) is gained from combining the various components and the difference can be attributed to emergence.
Understanding what emergence is and how it affects our world gives us a more holistic sense of complex systems and the role they play in our lives.
If we understand how emergence works, we can leverage that to improve our lives.