This graph shows the equilibrium point.
With supply and demand always see-sawing what do we really know about the financial state of this worlds trade? The supplier and producer have major parts in, how much the product price, how much there is and how easy it is to find. For instance a producer will pay for the product to be at eye level so that the consumer will notice the product.
Where the green and reed lines meet is called the equilibrium point, this is the point where the producer and the consumer are both happy.
For instance if a PC game wins an award the market is willing to pay more for the product, this can be called an economic relationship.
I learnt all this from brain pop