National debt is a public debt carried by the federal government of the country. National debt is a result of the financial borrowing of the country made to cover a deficit in the budget. There are two kinds of national debt, such as internal — which means the creditors are the residents of the country — and external — which means the creditors are from other countries. The first country in the world in terms of their national debt is Japan, and the country having the largest external national debt is the U.S. The U.S. national debt can be seen on the U.S. debt clock, set in the center of New York. In terms of cryptocurrency, Bitcoin — in some countries with a large national debt — was used as a way to store the value of money. Moreover, some countries use Bitcoin to pay its national debt.