Capitalism is an economic system based on the private ownership of the means of production and their operation for profit. The defining characteristics of capitalism include private property, capital accumulation, competitive markets, price systems, recognition of property rights, self-interest, economic freedom, meritocracy, work ethic, consumer sovereignty, economic efficiency, limited role of government, profit motive, a financial infrastructure of money and investment that makes possible credit and debt, entrepreneurship, commodification, voluntary exchange, wage labor, production of commodities and services, and a strong emphasis on innovation and economic growth. In a market economy, decision-making and investments are determined by owners of wealth, property, or ability to maneuver capital or production ability in capital and financial markets—whereas prices and the distribution of goods and services are mainly determined by competition in goods and services markets.

Economists, historians, political economists, and sociologists have adopted different perspectives in their analyses of capitalism and have recognized various forms of it in practice. These include laissez-faire or free-market capitalism, anarcho-capitalism, state capitalism, and welfare capitalism. Different forms of capitalism feature varying degrees of free markets, public ownership, obstacles to free competition, and state-sanctioned social policies. The degree of competition in markets and the role of intervention and regulation, as well as the scope of state ownership, vary across different models of capitalism. The extent to which different markets are free and the rules defining private property are matters of politics and policy. Most of the existing capitalist economies are mixed economies that combine elements of free markets with state intervention and in some cases economic planning.

Capitalism in its modern form emerged from agrarianism in England, as well as mercantilist practices by European countries between the 16th and 18th centuries. The Industrial Revolution of the 18th century established capitalism as a dominant mode of production, characterized by factory work and a complex division of labor. Through the process of globalization, capitalism spread across the world in the 19th and 20th centuries, especially before World War I and after the end of the Cold War. During the 19th century, capitalism was largely unregulated by the state, but became more regulated in the post–World War II period through Keynesianism, followed by a return of more unregulated capitalism starting in the 1980s through neoliberalism.

The existence of market economies has been observed under many forms of government and across a vast array of historical periods, geographical locations, and cultural contexts. The modern industrial capitalist societies that exist today developed in Western Europe as a result of the Industrial Revolution. The accumulation of capital is the primary mechanism through which capitalist economies promote economic growth. However, it is a characteristic of such economies that they experience a business cycle of economic growth followed by recessions.

In capitalist economics, market competition is the rivalry among sellers trying to achieve such goals as increasing profits, market share and sales volume by varying the elements of the marketing mix: price, product, distribution and promotion. Merriam-Webster defines competition in business as "the effort of two or more parties acting independently to secure the business of a third party by offering the most favourable terms". It was described by Adam Smith in The Wealth of Nations (1776) and later economists as allocating productive resources to their most highly valued uses and encouraging efficiency. Smith and other classical economists before Antoine Augustine Cournot were referring to price and non-price rivalry among producers to sell their goods on best terms by bidding of buyers, not necessarily to a large number of sellers nor to a market in final equilibrium. Competition is widespread throughout the market process. It is a condition where "buyers tend to compete with other buyers, and sellers tend to compete with other sellers". In offering goods for exchange, buyers competitively bid to purchase specific quantities of specific goods which are available, or might be available if sellers were to choose to offer such goods. Similarly, sellers bid against other sellers in offering goods on the market, competing for the attention and exchange resources of buyers. Competition results from scarcity, as it is not possible to satisfy all conceivable human wants, and occurs as people try to meet the criteria being used to determine allocation.

In the works of Adam Smith, the idea of capitalism is made possible through competition which creates growth. Although capitalism had not entered mainstream economics at the time of Smith, it is vital to the construction of his ideal society. One of the foundational blocks of capitalism is competition. Smith believed that a prosperous society is one where "everyone should be free to enter and leave the market and change trades as often as he pleases." He believed that the freedom to act in one's self-interest is essential for the success of a capitalist society. In response to the idea that if all participants focus on their own goals, society's well-being will be water under the bridge, Smith maintains that despite the concerns of intellectuals, "global trends will hardly be altered if they refrain from pursuing their personal ends. He insisted that the actions of a few participants cannot alter the course of society. Instead, Smith maintained that they should focus on personal progress instead and that this will result in overall growth to the whole.

Competition between participants, "who are all endeavoring to justle one another out of employment, obliges every man to endeavor to execute his work" through competition towards growth.