The Federal Reserve "prints" bank reserves, that's it. To understand why that matters, you have to understand where bank reserves came from and what they were and are intended for. It isn't at all what you think. But don't take my word for it; that comes straight from the Fed itself.
Eurodollar University's Money & Macro Analysis
FRB Atlanta The Evolution of the Check as a Means of Payment: A Historical Survey, November 2008
https://www.atlantafed.org/-/media/documents/research/publications/economic-review/2008/vol93no4_quinn_roberds.pdf
FRB Banking and Monetary Statistics 1914-41
https://fraser.stlouisfed.org/files/docs/publications/bms/1914-1941/BMS14-41_complete.pdf
FOMC Transcript July 1981
https://www.federalreserve.gov/monetarypolicy/files/FOMC19810707meeting.pdf
FOMC Transcript October 1979
https://www.federalreserve.gov/monetarypolicy/files/FOMC19791006meeting.pdf
FOMC Transcript March 1991
https://www.federalreserve.gov/monetarypolicy/files/FOMC19910326meeting.pdf
https://www.eurodollar.university
Twitter: https://twitter.com/JeffSnider_EDU
What is Eurodollar University?
Jeff Snider will guide you through the realm of monetary science. Multiple episodes uploaded each week, discussing big news and key current events, the state of markets and what they are telling you, as well as historical summaries and deep background material so that you can understand what’s really going on in this eurodollar’s world.