Public debt is when a country borrows money to cover its expenses. It can have both good and bad effects on the economy and society. The amount of public debt is influenced by factors like the government's budget and deficit. Countries use public debt to address social and economic issues, but it can also lead to problems if not managed properly. The size of the debt can be compared to the country's economic output to see if it's sustainable. Public debt is common in modern countries, but it shows a gap between economic potential and societal needs. Full repayment of public debt is often not possible due to its size.