Real price

A real price is a commodity price adjusted for inflation using a deflator, so that values from different years can be compared in constant purchasing power.

A real price strips out the effect of ordinary inflation, letting a comparison across years show whether a commodity actually became more or less valuable, rather than whether money itself lost purchasing power. A nominal price for gold today and a nominal price from decades ago cannot be compared directly, since a unit of currency bought far more in the earlier year.

Long-run charts of commodity prices are almost always shown in real terms for this reason; a nominal chart of almost any commodity slopes upward over a long enough period simply because currencies lose value over time, hiding whatever the commodity itself is doing. Claims about a commodity being at a multi-decade high or low should be checked against the real, inflation-adjusted series before being taken at face value. See nominal vs real prices.