There are two types of inflation: - PRICE INFLATION, which is typically what is tracked by the CPI. If the CPI was, say, 100 last year, and 105 now, it means t

There are two types of inflation: - PRICE INFLATION, which is typically what is tracked by the CPI. If the CPI was, say, 100 last year, and 105 now, it means there was 5% inflation in the price of the basket of goods tracked by the BLS. - MONETARY SUPPLY INFLATION. This is the total amount of currency in circulation. The US Federal Reserve publishes the M2 money supply. This is one factor that affects PRICE inflation (the first type), but if people don't spend a lot of the money supply each year, then prices don't increase a lot. The other factor affecting price inflation is MONETARY VELOCITY. As for what affects relative differences (some goods getting more expensive than the general inflation, while others not as much), it is supply or demand. As demand changed, especially during the pandemic, supply struggled to adapt and match it, and maybe overshot and so on. The economy is not a steady state.