Q.Explain the classification of public debt on the basis of

Public debt can be classified along two independent dimensions — where it comes from, and what it was borrowed for.

(a) By source:

• Internal Debt — borrowed from within the country, from the central bank, commercial banks, financial institutions, and the general public, typically through government bonds and treasury bills, repayable in domestic currency.
• External Debt — borrowed from outside the country, from foreign governments or international financial institutions, or through bonds issued in foreign currency; it carries the extra burden of repayment in foreign exchange, exposing the government to exchange-rate risk.

(b) By purpose:

• Productive Debt — raised to finance capital assets expected to generate income or returns over time, such as a power plant or railway line; in principle, such debt can be "self-liquidating" as the asset itself generates revenue to repay it.
• Unproductive Debt — raised to finance expenditure that creates no matching income-generating asset, such as war expenditure or covering a current revenue shortfall; it leaves future generations with a repayment burden but no corresponding asset to show for it. …

Treating 'internal vs external' and 'productive vs unproductive' as a single four-way mutually exclusive list rather than two SEPARATE, independent classifications — every …