Public Revenue sources funding government expenditures and development. Tax revenue: Direct taxes (income tax, corporate tax, wealth tax—assessed on income/wealth), Indirect taxes (GST, excise, customs—imposed on consumption/production). Tax characteristics: Progressive (higher earners pay higher rates), Regressive (lower earners pay higher proportion), Proportional (same rate for all), Non-tax revenue: Interest income from loans, Dividends from public enterprises, Licensing fees, Administrative charges. Borrowing: Domestic (government bonds, treasury bills, loans from banks), International (external loans, bilateral agreements), Creates debt obligations and interest payments. Grants and aids: International assistance, Grants from developed nations, Disaster relief. Seigniorage: Profit from issuing currency (rare, limited source). User charges: Utility bills, toll roads, permit fees. Revenue trends: Total government revenue composed of these sources; tax revenue declining as % of revenue in some countries (tax evasion, informal economy). Indian revenue: Income tax and GST are major sources; tax collection complexity in agrarian economy. ICAI focus: Sources classification, progressive vs. regressive nature. Exam tip: Distinguish tax from non-tax revenue; understand how each source affects different groups differently.