This document discusses different types of markets including product markets, resource markets, and competitive markets. It describes four types of market structures: monopoly, oligopoly, monopolistic competition, and perfect competition. These are categorized based on the number of firms, level of power, product differentiation, and ease of entry/exit. Perfect competition has many small firms with identical products and free entry/exit. Monopolistic competition has many firms with differentiated products and low barriers to entry. Oligopoly has a few dominant firms with significant control over price. Monopoly has a single firm with no substitutes and high barriers to entry.