ELI5: Explain Like I'm 5

World currency

Currency is the money that people use every day to buy things. Different countries have their own type of currency, such as the American "dollar" or the Japanese "yen." People all over the world use different currencies, so they need to exchange it when they buy things from another country. There are big banks that help people exchange the different currencies, so it's easier for people to buy goods from different countries.