what prima told me today, page-13

An American Depositary Receipt (abbreviated ADR) represents ownership in the shares of a non-U.S. company that trades in U.S. financial markets. The stock of many non-US companies trade on US stock exchanges through the use of ADRs. ADRs enable U.S. investors to buy shares in foreign companies without the hazards or inconveniences of cross-border & cross-currency transactions. ADRs carry prices in US dollars, pay dividends in US dollars, and can be traded like the shares of US-based companies.

Each ADR is issued by a U.S. depository bank and can represent a fraction of a share, a single share, or multiple shares of the foreign stock. An owner of an ADR has the right to obtain the foreign stock it represents, but US investors usually find it more convenient simply to own the ADR. The price of an ADR often tracks the price of the foreign stock in its home market, adjusted for the ratio of ADRs to foreign company shares