Trade is the exchange of goods or services among two or more parties. In its original form trade had to be negotiated through barter and the exchange of goods andservicesof a recognized equal value that was wanted by both parties. Modern trade is generally negotiated through the use of a medium of exchange, i.e. money, and rarely through barter: as a result one can separate buying and earning or selling. The invention of money greatly simplified and promoted the development of trade.
See also: International trade, Globalisation, Business, Retail.