The general increase of the prices of goods and services.
Stuff costs more; your money doesn't go as far as it did. The cost of living goes up.
Attitudes towards inflation have long been seen as a dividing line between left and right. Most Keynesians saw rising prices as a small price to pay for an otherwise healthy economy, given that tackling inflation tended to require higher interest rates, which curtail investment, output, and employment over the short term
Neoliberals, on the other hand, saw inflation as public enemy number one. First, rising prices eroded the real value of assets — if consumer prices are rising while house prices are stagnant, your house is worth less in real terms. Second, keeping interest rates low reduces returns from lending — important for profits in the finance sector — and low unemployment made it harder to discipline labour
The question we should therefore be asking is not ‘is inflation bad?’ The questions we should be asking are ‘which prices are rising, why are they rising, and who is bearing most of the impact