Dolar
In short
The US dollar is the main currency used for international trade and finance across the globe.
In plain words
It is the money used in the United States. Because many countries buy and sell goods using this currency, it acts as a global standard for value.
A simple example
If a shop in Japan wants to buy electronics from a company in Germany, they might use US dollars to settle the payment.
Why it matters
Most oil, gold, and major commodities are priced in dollars. Changes in its value can affect the cost of living in almost every country.
Easy to mix up
Do not confuse the US dollar with the Australian dollar or other currencies that also use the dollar name.