The value of money varies :

The value of money is defined as its purchasing power, which refers to the quantity of goods and services a single unit of currency can acquire [1]. There is a fundamental inverse relationship between the general price level and the value of money [1]. When the general price level increases (inflation), the purchasing power of money deteriorates because a unit of money can purchase fewer commodities than before [3]. Conversely, when prices fall (deflation), the value of money appreciates as it can buy more goods. This relationship is mathematically expressed in economic theories, such as Fisher's Quantity Theory, where the value of money is represented as the reciprocal of the price level (1/P). Therefore, the value of money varies inversely with the price level, meaning they move in opposite directions.

Sources

1. [1] Macroeconomics (NCERT class XII 2025 ed.) > Chapter 3: Money and Banking > 3.1 FUNCTIONS OF MONEY > p. 37
2. [3] Indian Economy, Vivek Singh (7th ed. 2023-24) > Chapter 2: Money and Banking- Part I > 2.29 Inflation > p. 112