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
Late Latin Augustan, post-Augustan and post-classic or late Latin, which indicates the term already was in professional use by English classicists in the early 19th century. Instances of English vernacular use of the term may also be found from the 18th century. The term Late Antiquity meaning post-classical and pre-medieval had currency in English well before then. Wilhelm Sigismund Teuffel's first edition (1870) of "History of Roman Literature" defined an early period, the Golden Age, the Silver Age and then goes on to define other ages first by dynasty and then by century (see under Classical Latin). In subsequent editions he subsumed