National debt
The accumulated total the federal government owes, built up from every past year's deficits and surpluses.
Two figures circulate and they are not the same. Debt held by the public is what the government owes to outside holders — individuals, funds, foreign governments, and the Federal Reserve. Gross federal debt adds intragovernmental holdings, chiefly the balances credited to trust funds such as Social Security.
For questions about the government’s borrowing in financial markets, debt held by the public is the relevant number. For questions about the statutory debt limit, the gross figure is the one that binds.
Usually quoted as total public debt outstanding. It is worth checking whether a figure means debt held by the public or the gross total, which includes what the government owes itself.