Inflation means not the price increase of a single product, but a rise in prices overall. It is measured by a consumer basket — a fixed set of goods and services whose cost is compared with the previous period.
Personal inflation almost always differs from official inflation, and this is not a sign of data distortion. The index reflects the average structure of expenses, while a specific family has its own shares of food, rent, transportation, and services. Those who spend most of their income on food experience food inflation more strongly than the average indicator.
Core inflation is singled out separately — a calculation that excludes the most volatile components such as fruits and vegetables and regulated tariffs. It poorly reflects consumer sentiment but more accurately shows the sustained trend to which monetary policy responds.
For an investor, inflation is a minimum benchmark. Real return equals nominal return minus price growth, and an investment with a rate below inflation preserves the sum but not purchasing power. This is why comparing deposit rates should be done not with last year's rate, but with current price growth.