Since the people started to live on our planet, they have rapidly found out that it is almost impossible to reach everything on their own. We have fast observed that we have to work with each other, because of the fact that somebody has something in too big amounts and others too little. That’s the reason why, plenty of decades ago the trade started. The main fact connected with it is to exchange goods, or products for money in such relation that will satisfy both parties. As a result, it is impossible to force a partner in a trade to accept such conditions that will be unacceptable for him.