What is it?
The Debt Clock is a counter that tracks the amount of the US National Debt, and displays an estimate of the current amount of debt. The US National Debt represents the sum of all budget deficits minus surpluses plus any other obligations the US has taken on. In essence, it’s how much the United States owes in debt much like a Mortgage.
Where is it?
There is no physical clock, this is a imaginary clock based on the current value of the very real National Debt. The US Treasury publishes the amount of US Debt and updates it regularly on the US Debt to the Penny site. Many Debt Clock manifestations, both physical and electronic, show up using this data or similar data, often simulating the motion of the spend based on the rate of spend between reporting cycles from the US Treasury.