Monopoly – this term is used in the Commercial Law, where details a commercial advantage in favor of only one or a selected few companies in which only those companies can trade in a certain area, where harming their cometitors on the local market and seeking increasing their profit from such activities. Monopols are harmful for the democratic bases of each society, but yet some monolopoies are legal, such as those temporarily created by patents. Others are secretly built by conspiracy between two or more companies and are prohibited by law.

See also http://www.investopedia.com/terms/m/monopoly.asp#axzz1cS9cOASq .