Meaning:

Public debt refers to the total amount of money owed by the government to creditors, both domestic and foreign. It is the accumulation of past borrowing by the government through issuing bonds, bills, and other securities to finance its expenditures when its revenue falls short of its spending. Governments often borrow money to finance infrastructure projects, social programs, defense, and other public services. The types of public debt expresses the nature of debt.

Types of Public Debt:

1. Internal and external debt: Internal debt refers to the public loan raised from inside the country and external debt refers to the loans taken by the government from individuals, institution and government of foreign countries or from international financial institution the interest burden on internal debt does not post much of a problem as it affects the redistribution of income within the country. But the interest burden of external debt and its repayment causes hardships in the economy as this have to prepare in terms of foreign currency resulting in Outlook income abroad.
2. Productive and unproductive public debt: When a debt is used by the government directly for productive purposes it is called productive debt. For example it is used for the project which yields and income like railways, power projects and irrigation projects etc.  Unproductive debt is that debt which is not use directly for productive purposes. For example it is used for those projects which do not yield any income like for financing war, meeting emergencies like floods, earthquakes, etc. productive debt adds to the total production capacity of the economy whereas the unproductive debt does not add to the productive capacity of the country and productive debt is also called dead weight debt as it puts a burden on the government and its repayment is also difficult.
3. Redeemable and irredeemable public debt: When the government promises to pay off the depth at some predetermine future that it is called redeemable debt. The government generally pays interest on these debts on regular basis. irredeemable public debt is the debt where the principle amount is never return and the government does not promises to repay at anytime in future but interest on such that is paid regularly. Irredeemable debt is rare in real life.
4. Funded and unfunded public debt: Public debt for the payment of which the government makes a separate fund is called funded public debt. every year the government credits certain amount of money in this fund and on maturity the debt is repaired out of this one whereas the government does not create any separate fund for the repayment of any debt. That debt is term as unfunded debt. The interest on this debt is paid by the government out of its regular inflow and the principal amount is repaid by taking additional loans from the market. Sometimes the unfunded debt is referred to as floating debt and they are generally for short period, to be repaid within a year.
5. voluntary and forced public debt: Voluntary debt is rise from the public on a voluntary basis and does not involved any element of coercion people give such loans on their own. On the other hand compulsory or forced debt is that which is taken by the government even against the wishes of the people such loans rose in case of national crisis like war.

also read: explain the types of public expenditure.