Currency today is used to purchase items one person needs or wants. When you go to the grocery store and by food you are using currency to pay your debt to the store. you can also use currency to fly to different countries. Currency  can be used millions of ways so use your currency wisely it may not be there when you need it. Different countries have different currencies, The U.S. has the dollar Great Britain has the British pound and other countries. Russia has the Euro as many other countries do. Every country has their own kind of currency.