I just remembered something that many people don't know well: the US dollar has several ways to be abbreviated. The most common is USD, which is the official code according to ISO 4217 standards, but you also see the symbol $ everywhere. Basically, USD is how dollars are officially abbreviated in international transactions.

The interesting thing is that the dollar is not only the currency of the United States, but it is practically the global reference currency. There are countries that don't even issue their own real currency; they simply use dollars directly or peg their currency's value to the dollar. It's as if the entire world agrees to use the dollar as a standard.

All of this is managed by the American Federal Reserve, which is the central bank responsible for issuing dollars. That's why any decision made there affects almost all economies. When you see USD on any trading or exchange platform, you already know we're talking about the most important currency in the international financial system.