Inflation refers to a continuous rise in general price level, which shrinks the value of money or purchasing power over a certain length of time. It is calculated in terms of per cent change in the value of price index consisting of a range of goods or services. An inflation rate of 8% means that the general level of prices of goods and services has increased by 8% over the previous period.

In other words, purchasing the same amount of goods and services will cost you 8% more than what it would have cost you in the previous period. Thus, Inflation can also be explained as a decline in the real value of money - a loss of purchasing power in the means of exchange, which is also the monetary unit of account.

There are several inflation measures available in India – the most commonly used are based on Consumer Price Index (CPI) and Wholesale Price Index (WPI). Within these, there are several sub-indices (e.g. CPI for Industrial Workers, CPI for Urban Non Manual Labourers, etc.) as well. These sub-indices are designed to see how price increases affect different set of people. Since WPI is available on a weekly basis, inflation based on that is the most commonly referred inflation measure in India.