We will start with the premise that we are interested in things that are connected. Never mind now why, for now it is sufficient just to state that we are interested in such a connection of things. To make coversation easier, rather than always saying ‘the collection of things that are connected’ we will attach the label ‘system’ to this collection. To be clear, we shall define a system as any cohesive collection of items that is dynamically related.   more »