But - the government spends money - to pay civil servants, pay Medicare bills, VA, buy fighter jets and aircraft carriers, etc. It also takes in assorted tax revenues. However, the federal government - the assorted departments - spend a lot more than the IRS collects; so to pay for that stuff, they also sell T-Bills, in a roundabout way - i.e. refinance the mortgage on the government. That borrowed money goes into federal accounts to help pay for all the things that the IRS revenue was not enough to cover. Essentially, the Fed sells bonds on behalf of the working government’s deficit.
Yes, the Fed can also “make up” money or electronic transfers. Basically it’s the keeper of loans and deposits for the entire banking system. Banks that need temporary liquidity get an overnight loan from the Fed. If the Fed says “ABC Bank, you now have a loan for an extra hundred million” everyone believes them. If the Fed buys the Treasury bills and says “Treasury, you now have an extra hundred billion” then everyone believes them. Standard rates may apply…
At least with the banks, the regulations are supposed to ensure the banks keep enough money at hand to cover eventualities, so that a bank does not need the Fed loan to stave off bank failure; so those loans to banks that add to the money supply are optional, and when the Fed needs to scale back they can safely make them more expensive (higher interest) with out crashing the system.
But both those sources are part of the money supply. If the money supply gets too big too fast, it causes inflation. Everyone is flush with cash, nobody discounts what they sell (or they raise prices) because a lot of entities seem to have plenty of money… People see all this money floating by and demand higher wages.
Places like Argentina, Zimbabwe, Nicaragua, Weimar Germany and post-Soviet Russia did not understand this (or did not care). When there’s too much money for the amount of goods in circulation, you get serious inflation. (And by contrast, when there’s too little money, you get deflation and depression, where when nobody has money, nobody can sell anything, prices drop.)
The goal of the Fed is to keep the money supply in the right range. With and without QE, they’ve actually done a pretty good job after the inflation of the 1970’s.