Reserve currency economy, the German Deutsche Mark gained the status of the second most important reserve currency after the US dollar. When the euro was introduced on 1 January 1999, replacing the Mark, French franc and ten other European currencies, it inherited the status of a major reserve currency from the Mark. Since then, its contribution to official reserves has risen continually as banks seek to diversify their reserves, and trade in the eurozone continues to expand. Former U.S. Federal Reserve Chairman Alan Greenspan said in September 2007 that the euro could replace the U.S. dollar as the world's primary reserve currency.
Language and the euro the same as the unit of measurement of time or of angle. The term , plural ("evroleptó", plural "evroleptá") is sometimes used when a speaker wants to be completely specific that they are referring to money and not time. Some colloquial names for currency are also in use for the euro. One and two euro coins are respectively called ("frago") and ("difrago") from the French "franc". A 5 euro banknote is also colloquially called ("taliro") from the Germanic root "thaler" via the Italian "talero". A 10 euro banknote is called ("dekariko"), a 20 euro banknote is called ("eikosariko") or ("eikosari"),