This is a standard measure of inflation that has been adopted across Europe.
The US inflation measure goes by the same name. It measures the change in prices of a standard basket of goods consumed by a typical family over a month. It matters because many payments made to savers and pensioners may be linked to it (or another inflation measure known as the retail price index) and central banks often base their interest rate decisions, in part, on the level of this index. The CPI measure the cost of regular items of expenditure such as food, utilities and petrol but does not include property related costs such as mortgage interest and council tax.