World currency

In the foreign exchange market and international finance, a world currency, supranational currency, or global currency refers to a currency in which the vast majority of international transactions take place and which serves as the world's primary reserve currency. In March 2009, as a result of the global economic crisis, China and Russia have pressed for urgent consideration of a global currency and a UN panel has proposed greatly expanding the IMF's SDRs or Special Drawing Rights.

Currencies have many forms depending on several properties: type of issuance, type of issuer and type of backing. The particular configuration of those properties leads to different types of money. The pros and cons of a currency are strongly influenced by the type proposed. Consider, for example, the properties of a complementary currency.

source: http://en.wikipedia.org/wiki/World_currency