The process by which the various countries of Europe are becoming more closely linked, particularly in trade and finance. This is partly the result of natural economic developments: trade has increased mainly because of the rise of intra-industry trade, which is increasingly important in industrialized countries situated close together; financial links have been fostered by the general move to abolition of exchange controls and financial deregulation. Integration has also been promoted by deliberate policy, as shown in the formation of numerous European institutions, of which the main ones are the European Community, now the European Union, the European Free Trade Association, and the European Monetary Union, with the euro as a common European currency.