If a basket of everyday goods cost $100 a year ago and costs $103 today, inflation is 3%. Prices are still rising when inflation falls; they are just rising more slowly. In the US it is measured mainly by the CPI and the PCE price index, and the Federal Reserve aims for 2% a year.
Higher inflation usually means higher interest rates for longer, which tends to weigh on stocks and crypto. This is a different thing from token inflation, which is the creation of new coins by a blockchain or project.
Example
US consumer prices rose 9.1% in the 12 months to June 2022, the fastest pace in four decades, and the Fed raised rates quickly in response.