What is Government Debt?

Legal Definition
Government debt (also known as public interest, national debt and sovereign debt) is the debt owed by a central government. (In federal states, "government debt" may also refer to the debt of a state or provincial, municipal or local government.) By contrast, the annual "government deficit" refers to the difference between government receipts and spending in a single year.

A central government with its own currency can pay for its spending by creating money de novo, but Government debt is generally generated to offset the deficit when spending exceeds receipts. This practice stems from a desire to impose discipline on government spending and to avoid hyperinflation.

Governments usually borrow by issuing securities, government bonds and bills. Less creditworthy countries sometimes borrow directly from a supranational organization (e.g. the World Bank) or international financial institutions.

As the government draws its income from much of the population, government debt is an indirect debt of the taxpayers. Government debt can be categorized as internal debt (owed to lenders within the country) and external debt (owed to foreign lenders). Another common division of government debt is by duration until repayment is due. Short term debt is generally considered to be for one year or less, long term is for more than ten years. Medium term debt falls between these two boundaries. A broader definition of government debt may consider all government liabilities, including future pension payments and payments for goods and services the government has contracted but not yet paid.
-- Wikipedia
Legal Definition
Government-and-agencies-issued debt securities, fully backed by faith and credit, tallied to an aggregate value.