中文：

准备金率是指商业银行必须存放在中央银行或金融监管部门的准备金的比例，通常以百分比的形式表示。准备金率是央行或金融监管部门为了控制银行信贷规模、防范金融风险而制定的政策措施。

在银行体系中，准备金率的高低直接影响到银行的信贷规模和资金成本。如果准备金率提高，银行必须存放在中央银行或金融监管部门的资金增加，银行的资金成本上升，信贷规模受到限制；反之，如果准备金率降低，银行可用于贷款的资金增加，信贷规模扩大，资金成本下降。

央行或金融监管部门通过调整准备金率可以有效地调控宏观经济运行。在经济过热、通货膨胀压力增大时，央行可以采取提高准备金率的措施来控制银行信贷规模、抑制通货膨胀；而在经济衰退、通货紧缩时，央行可以采取降低准备金率的措施来刺激经济增长、促进物价稳定。

英文：

Reserve ratio refers to the proportion of reserves that commercial banks must deposit with the central bank or financial regulatory authorities, usually expressed in percentage form. The reserve ratio is a policy measure formulated by the central bank or financial regulatory authorities to control the credit scale of banks and prevent financial risks.

In the banking system, the reserve ratio directly affects the credit scale and funding costs of banks. If the reserve ratio increases, the amount of funds that banks must deposit with the central bank or financial regulatory authorities will increase, the funding costs of banks will rise, and the credit scale will be restricted. Conversely, if the reserve ratio decreases, the amount of funds that banks can use for loans will increase, the credit scale will expand, and the funding costs will drop.

The central bank or financial regulatory authorities can effectively regulate the macroeconomic operation by adjusting the reserve ratio. When the economy is overheating and inflationary pressure is increasing, the central bank can adopt measures to increase the reserve ratio to control bank credit and curb inflation. While in economic recession and deflation, the central bank can take measures to decrease the reserve ratio to stimulate economic growth and promote price stability.