A currency is the most common form of money used by people around the world. This most common form of money is used by people for medium of exchange for buying things and goods. The list of most popular currencies includes US dollar, Chinese yuan, Australian dollar, Japanese yen, Eyri and English pound. These currencies can be easily considered as permanent store of value and they are traded between different nations for exchange of goods. The value of currencies is determined by governments, market dynamics and various limitations imposed by countries.