Money is an agreed upon medium of exchange and store of value or just a medium of exchange.

Modern fiat is just a medium of exchange in most countries, and if you are in a country with it's own printing press powers there are several ways in which it is produced, but the debt as money has far outpaced the printing press.

Debt as money is not inherintly a bad thing, but interest on that debt is.  Let's assume for the sake of argument there is no printing press and all money comes from a promised debt with some amount of interest.  You have 100 people "borrow" into existence 20 dollars each so there is now $2000 dollars in the economy, and it is all borrowed at 10% non-compounding interest for a total of $200 in interest.  Now the money lender turns off the borrowing faucet because they have taken on too much "risk" or they are retiring... whatever reason.  $2000 (current total in circulation) / $22 (Principle + Interest paid in full) = 90.909... (The number of people who *could possibly have a chance to pay off their loan in full, because in the realm of fake money once the $ is paid back it ceases to exist again.)

This is why debt based monetary creation has exploded and why the printing presses have no hope to keep up and this is the race the world is in now, so long as the money creation can outpace healthy repayment then economies move along swimmingly but as soon as the Interest monster starts catching up and potentially exceeding what an economy can sustain then collapse is inevitable.