A market is any one of a variety of different systems, institutions, procedures, social relations and infrastructures whereby persons trade, and goods and services are exchanged, forming part of the economy. It is an arrangement that allows buyers and sellers to exchange things. Markets vary in size, range, geographic scale, location, types and variety of human communities, as well as the types of goods and services traded. Some examples include local farmers' markets held in town squares or parking lots, shopping centers and shopping malls, international currency and commodity markets, legally created markets such as for pollution permits, and illegal markets such as the market for illicit drugs.

In mainstream economics, the concept of a market is any structure that allows buyers and sellers to exchange any type of goods, services and information. The exchange of goods or services for money is a transaction. Market participants consist of all the buyers and sellers of a good who influences its price. This influence is a major study of economics and has given rise to several theories and models concerning the basic market forces of supply and demand. There are two roles in markets, buyers and sellers.

The historical origin of markets is the physical marketplaces which would often develop into small communities, towns and cities.Fact: date=July 2008

Types of markets

Although many markets exist in the traditional sense — such as a marketplace — there are various other types of markets and various organizational structures to assist their functions. The nature of business transactions could define markets.

Financial markets

Financial markets facilitate the exchange of liquid assets. Most investors prefer investing in two markets, the stock markets and the bond markets. NYSE, AMEX, and the NASDAQ are the most common stock markets in the US. Futures markets, where contracts are exchanged regarding the future delivery of goods are often an outgrowth of general commodity markets.

Currency markets are used to trade one currency for another, and are often used for speculation on currency exchange rates.

The money market is the name for the global market for lending and borrowing.

Prediction markets

Prediction markets are a type of speculative market in which the goods exchanged are futures on the occurrence of certain events. They apply the market dynamics to facilitate information aggregation.

Organization of markets

A market can be organized as an auction, as a private electronic market, as a shopping center, as a complex institution such as a stock market, and as an informal discussion between two individuals.

Markets of varying types can spontaneously arise whenever a party has interest in a good or service that some other party can provide. Hence there can be a market for cigarettes in correctional facilities, another for chewing gum in a playground, and yet another for contracts for the future delivery of a commodity. There can be black markets, where a good is exchanged illegally and virtual markets, such as eBay, in which buyers and sellers do not physically interact during negotiation. There can also be markets for goods under a command economy despite pressure to repress them.