Perfect Competition, Monopolistic compeition, oligopoly markets, an monopoly is charachertized by? Quantity of firms, barriers to entry, nature of products, nature of competitors and pricing power.
Perfect Competition - Lot of competiion, low barriers to entry, products are very good substitues for one another, price only, no pricing power.
Monopolistic competion - Lot of competition, low barriers, products are good substitues but differentiated a bit, price advertising and quality, low pricing power
Oligopoly - Few competition, high barriers, products are good subs or differentiated, price advertizing quality, good pricing power.
Monopoly - one firm, high barriers, no substitues, advertising, pricing poewr is extremely high