Foreign direct investment (FDI) is a term for a direct investment in a company or a business from another country. Foreign direct investments are investments made by a particular investor in a particular company - unlike portfolio investment in financial markets.
Foreign direct investments in practice: Investments designated as FDI must be at least 10% stake in the company (purchase of shares, or other business interest). The investor typically receives significant decision-making power in the company, where he invests.
In terms of the system of national accounts FDI is part of the statistics of balance of payments, specifically its financial account.