You should watch the series [Hidden secrets of money](https://www.youtube.com/playlist?list=PLE88E9ICdiphYjJkeeLL2O09eJoC8r7Dc) is very well explained there.
For Es in particular, works the same as for any other place but soon they will drop it.
They kept USD still as a currency just because they can't make the transition  just like that from one day to another. But soon they will drop it, as long as people will start learning what is Bitcoin.

DarthCoin

Fyi. Fed does not create money to put them in bank. Bank “creates” them by using other clients’ dollars while keeping those balances “untouched”

inverselarp

bitcoin

In the US when a commercial bank issues a loan, e.g. a mortgage, the Fed creates money and puts it in the bank, so the bank can lend it to the borrower.

Now, how does it work in other countries that use the USD? Does the Fed put dollars in a bank in El Salvador when someone takes out a USD mortgage there? Or does the Salvadoran banking system use 'monopoly dollars', i.e. database entries that are not (or not completely) redeemable for 'real' USD?