Monopoly, when an individual or enterprise has such control over a particular product or service to be able to decide the terms on which others may use it.  There is no economic competition for the good or service and no suitable substitutes.

It can also be that a firm gains greater market share than is logical in a situation of 'fair' competition.

In this article you can:

			read about some aspects of monopolies
			listen to a legal adviser talking about anti-trust cases
			learn some related vocabulary and collocations