Inflation is triggered by a rise in the cost of goods & services (stuff). It becomes a big problem when wages & income don’t rise at the same level.

In the US, the Federal Reserve works to keep inflation between 2-4%. But if your paycheck isn’t growing by more than that each year you’re actually losing “purchasing power” (the ability in the future to purchase the same amount of stuff as before).

Currently (Nov 2021) a conservative measure of the US inflation rate is about 6%. Any money sitting in a savings account will be able to buy 6% less goods or services next year.