M1 is the total currency in the banks + checking accounts.
M2 = M1 + savings accounts, funds
Money supply measures the amount of currency in circulation in the economy and is, as a consequence, a measure of future inflation. If you would think that the government isn't still printing money, I need to dissapoint you. M1 and M2 are still rising at an exceptionally fast pace. Which is very inflationary in the future.