Bank notes, also commonly referred to as paper currency, are a form of payment created by a central bank and used as legal tender in a country. They are also often referred to as bills, bank paper, cash, or money. The word "currency" is another synonymous term, which is commonly used to refer to bank notes in circulation. In addition, many countries have their own terminology for bank notes, such as "notes" in the UK and "bills" in the US. Other synonyms for bank notes may include bankroll, bread, dough, loot, moolah, and greenbacks. Regardless of the terminology, bank notes play a significant role in global economics as a form of currency used to facilitate trade.