Simply put, "currency" refers to banknotes (banknotes) and coins (coins) issued by the central bank of a country; However, money is only a kind of money, and the essence of money is not simply described by money or cash in economics.
Money is a part of money as a medium of exchange, and it is also a part of money supply in various countries that does not need endorsement. It only includes paper money and coins, excluding the storage function of money and other means of payment. The currencies of different countries are exchanged according to the exchange rate in the monetary field, which can be divided into fixed exchange rate and floating exchange rate due to different exchange rates.
All countries generally control the supply and demand of their own currencies, with the exception of the European Union. The European Central Bank controls the monetary policies of all EU countries in a unified way.
The monetary system can be divided into legal tender, commodity currency and representative currency, depending on how the price of the currency is determined (whether it is determined by the overall economy or by the government's precious metals or foreign exchange reserves). Some currencies have legal solvency in other countries, but the proportion is not high.
Because of the popularity of computers and the Internet, digital currency is becoming more and more popular. However, it is uncertain whether digital currency can be successfully promoted. Decentralized digital currency (such as cryptocurrency) is not legal tender, because it is not issued by the financial department of the government and has no legal payment capacity. Many countries have also warned that digital currency may be used for illegal activities (such as money laundering or terrorism).
hard currency
Hard currency in economics (English: hard currency? Or? Strong currency) refers to the currency that is traded on a global scale and can be used as a reliable and stable storage means.
There are many factors to ensure that a currency is "hard" enough, including political stability, low inflation, stable monetary and fiscal policies, sufficient precious metal reserves, and long-term stability or rise in the exchange rate with other currencies.