A System is made up of three kind of things:
- Stocks aka Elements
- Interconnections
- Function(s) / Purpose(s)
For example: the digestive system, a football team, the solar system, a tree, a forest, …
What is not a system? A conglomeration of things that are not interconnected. For example: sand next to the road. You can add some (elements), remove some -> there is no change (but quantitative).
On the other hand: add/remove players -> changes the whole game. Add/remove planets -> changes the whole solar system. And so on for all systems
Parts of the system may or may not be changed:
- trees loose and regrow their leaves, without suffering fundamental change (unless catastrophe)
- Football players in a team may be changed, effect can be significant - bad or good - or nothing at all
