Money is legal tender issued by a government, including paper currency and coin. Other negotiable instruments and cash on deposit in banks are also considered to be money. The supply of money in the economic system of a country is monitored very carefully and measured on a regular basis by governmental authorities. The most common measures of money supply are M1, M2, and M3. Most economists would agree that economic growth and inflationary trends of a country are determined by money supply. Money supply in the United States is managed mainly by the Federal Reserve Board through its bank reserve requirements, the discount rate it charges to banks for money, as well as its open market operations conducted through the issuance of securities.

钱币是政府发行的法定货币，包括纸币和硬币。其他可流通票据和现金存款也被认为是货币。一个国家经济体系的货币供给受到政府当局的严密监控及定期调节。通常调节的货币供给是M1,M2,M3。大多数经济学家认为一个国家的经济增长和通货膨胀趋势取决于货币供给量。美国的货币供给主要由联邦储备局进行管理，包括银行准备金，通过贴现率收费以及通过发行证券公开市场业务