It is the financial system and trading of currencies among banks and financial institutions, excluding retail investors and smaller trading parties. While some interbank trading is performed by banks on behalf of their large customers, most interbank trading takes place from the banks' own accounts.

It is the deliberate downward adjustment to a country's official exchange rate relative to other currencies. In a fixed exchange rate regime, only the decision by a country's government (i.e central bank) can alter the official value of the currency. This is the opposite of "revaluation". There are two major effects of a currency devaluation. First, devaluation makes a country's exports relatively less expensive for foreigners and second, it makes foreign products relatively more expensive for domestic consumers, discouraging imports. As a result, this may help to reduce a country's trade deficit.