IOUs are money

We think of creating money as the government's job. But actually, anyone can create money by writing an IOU. In fact most of the money supply is created by non-government entities.

If I loan you a dollar, then you now have the dollar, and I have your IOU valued at $1. Now there are $2 of dollar-denominated assets in the world where previously there was only the one dollar.

Domestic banks have a somewhat special status with regard to money creation: only they can write IOUs that are guaranteed to be worth a dollar. The IOUs you write are effectively their own asset class, whose risk fluctuates according to your personal financial circumstances. But banks are regulated and ultimately backed by the Federal Reserve (central bank); their IOUs are dollars. The process of creating money through bank loans is called fractional reserve banking.

A dollar-denominated IOU from a foreign bank is a eurodollar.

Corporate bonds or 'commercial paper' also create money. Buying a $100 bond issued by Apple is akin to depositing $100 at the 'bank of Apple', which then 'loans out' the cash as investments in Apple's business. Apple has your $100, but you now hold a bond valued at $100, so the original $100 has turned into $200 of assets. Just as with a bank, the hope is that enough of the investments pay off that Apple is able to repay your money with interest. But unlike a bank, Apple faces no reserve requirement and its liabilities are not government insured.