Currency refers to the system of money used in a particular country or region as a medium of exchange for goods and services. It is a means of facilitating trade and commerce by providing a standardized unit of value.

Currencies can take different forms, such as coins or banknotes, and may have subdivisions like cents or pence. Each currency typically has a specific symbol or code associated with it to distinguish it from other currencies. For example, the symbol for the United States dollar is "$" and its currency code is USD.

Currencies can be classified into two main categories: fiat currency and commodity-backed currency. Fiat currency has value because the government declares it as legal tender, and people accept it as a medium of exchange. Commodity-backed currency, on the other hand, is backed by a physical commodity, such as gold or silver.

Exchange rates determine the value of one currency relative to another. These rates fluctuate based on various factors, including economic conditions, interest rates, political stability, and market forces. Exchange rates play a crucial role in international trade and finance, as they determine the cost of importing and exporting goods and services between countries.

Central banks, such as the Federal Reserve in the United States or the European Central Bank in the Eurozone, typically have the authority to regulate and control the supply of money, set interest rates, and intervene in currency markets to stabilize their respective currencies.

It's important to note that currency-related information is subject to change, so it's always a good idea to consult the latest financial sources or financial institutions for the most up-to-date information regarding specific currencies and exchange rates.