Imperfect markets lack perfect competition, such as in the case of monopolies. For example, consider the search engine and digital advertising marketplace.

Unlike perfect competition, where numerous small firms compete with identical products, imperfect competition is characterized by fewer firms, differentiated products and barriers to entry. This ...

The opposite of perfect competition is imperfect competition, which exists when a market violates the abstract tenets of neoclassical pure or perfect competition. Jessica Olah / Investopedia.