An organization chart is an example of a graph: the nodes are interpreted as positions in the organization, and the links, the reporting and authority lines.
Every dance is a kind of fever chart, a graph of the heart.martha graham
"Linear relationships can be captured with a straight line on a graph. Linear relationships are easy to think about....Linear equations are solvable... Linear systems have an important modular virtue: you can take them apart, and put them together again the pieces add up."