Money, that physical stuff in your pocket, under your mattress, or in your safe, is cash created by the central bank responsible for that currency. So, if it's Canadian dollars, it's the Bank of Canada (BoC) that issues that money. If it's US dollars, then it's the Federal Reserve (Fed) that issues the currency. Most people believe this physical money is issued by their government. They might be wrong.
You see, the BoC, for example, is majority "owned" by the Canadian ministry of finance. The finance minister has the shares to the bank in his desk. But the Fed system (there are 12 regional banks), at law, is owned by private commercial banks. There's a big difference here. US dollars are not minted by the government, but Canadian dollars are.
It's also important to understand how this money comes into existence. Who owns it when it's created? When central banks "mint" physical notes and coins, it turns into an asset
on their accounting books (a positive value). At the same time, those notes and coins turn into a liability
for whomever borrowed them from the central bank. In other words, it's something that someone needs to pay back! When that someone does
pay the balance back, the central bank effectively destroys the money it initially created. Cool, huh? For this reason, money is debt. From its very existence, physical cash is a promissory note or coin that must be paid back in full. Once it is, it's gone forever. Remember that.
Of course, central banks don't go hunting for their money back just to burn it. They let it circulate for many years to provide "liquidity" for people to buy and sell things - that is, for the purpose of trade. You don't have an economy if nothing trades, and cash is one way of providing oil to grease the economic engine.