Currency relative values of the different currencies. Currencies in this sense are defined by governments, and each type has limited boundaries of acceptance. Other definitions of the term "currency" are discussed in their respective synonymous articles banknote, coin, and money. The latter definition, pertaining to the currency systems of nations, is the topic of this article. Currencies can be classified into two monetary systems: fiat money and commodity money, depending on what guarantees the value (the economy at large vs. the government's physical metal reserves). Some currencies are legal tender in certain political jurisdictions. Others are simply traded for their economic
Evolution (term) Evolution (term) The English noun evolution (from Latin "unfolding, unrolling") refers to any kind of accumulation of change, or gradual directional change. It is the 3,117th most commonly used word in English. While the term primarily refers to biological evolution, there are various types of chemical evolution and it is also found in economics, historical linguistics, and many other technical fields where systems develop or change gradually over time, e.g. stellar evolution, cultural evolution, the evolution of an idea, metaphysical evolution, spiritual evolution, etc. The English term prior to the late 19th century was confined to referring to goal-directed, pre-programmed