From ArticleWorld

A market is a social arrangement that allows buyers and sellers to carry out a voluntary exchange. A market may be a physical place set up for face-to-face meetings, or it may be through the mail or over the Internet.

Supply and demand

Markets must make adjustments to prices to keep up with supply and demand. For example, if more buyers want a certain good than is available from sellers at a given price, the solution requires either that buyers reduce their demand for the item, or that sellers produce more of the item. These results are accomplished by a rise in the price of that good. Some buyers will refuse to pay the higher price, while more sellers are willing to offer the good at the increased price. In cases where more of an item is available than people will buy, the reverse effect will make the choices of buyers and sellers compatible. In this way, markets are very efficient.

Free and barter markets

A free market is one where the government makes no attempt to intervene. There are no taxes, minimum wages, or price ceilings. No national economy, in existence today. fully manifests the ideal of a free market. In political terms, the phrase free market economy usually refers to an economy that approximates the ideal, by virtue of having a government that engages in little or no economic regulation.

Barter markets rely soley on the trade of goods and depend upon mutual need. They are most common in societies where no monetary system exists, or in economies with very unstable currency.