Some info about the national
debt
Exports minus imports is just the trade surplus (or deficit if it's negative). This is a figure that applies to a given year only and is part of the calculation of GDP. It is important because of its volatility and impact on currency rates which, in turn, affect the economy.
The national debt, on the other hand, is an accumulated figure that's been accumulating for over 200 years. It is basically the accumulated
budget deficit, ie. the amount that the government spent in excess of what it collected in revenues.
The largest chunk of that debt is owed to the Federal Reserve (the Fed), which is a
privately owned corporation -- a fact very much downplayed by the government and media. One source of info. about the Fed is
here , which some will say is negatively biased but which I personally think is accurate.