Trade involves the transfer of goods or services from one person or entity to another, often in exchange for money. Economists refer to a system or network that allows trade as a market.
An early form of trade, the Gift economy, saw the exchange of goods and services without an explicit agreement for immediate or future rewards. A gift economy involves trading things without the use of money. Modern traders generally negotiate through a medium of exchange, such as money. As a result, buying can be separated from selling, or earning. The invention of money greatly simplified and promoted trade. Trade between two traders is called bilateral trade, while trade involving more than two traders is called multilateral trade.
In one modern view, trade exists due to specialization and the division of labor, a predominant form of economic activity in which individuals and groups concentrate on a small aspect of production, but use their output in trades for other products and needs. Trade exists between regions because different regions may have a comparative advantage in the production of some trade-able commodity—including production of natural resources scarce or limited elsewhere.