Sellers in a monopolistic competition try to differentiate or point out differences in their products and those of their competitors.
The main goal for product differentiation and non price competition is to increase profits.
Interdependent pricing is being responsive to or dependant on the pricing action of competition.
Collusion is sellers secretly agree to set production levels or prices for their products, it is illegal.
Natural Monopoly is a market in which a single monopoly produces a good or service most efficiently.
"Trusts" are another word for huge monopolies.
The first antitrust law was the Interstate commence law.
Standard Oil was the best known monopoly to be broken up by the Sherman antitrust law.