Commercial Revenue
Commercial revenue is called earned revenue. Income from state domain like revenue from mines, minerals, forests, rivers, mountains etc. in the form of royalty and duties is called earned income.
Revenue from public enterprises is received in the form of price. Public enterprises are those undertakings which are owned, operated and managed by the state. Revenues received from railways, post and telegraph, oil and gas supply, water supply, civil aviation, etc. called commercial revenues. The public enterprises sell the product and services to the people and collect revenue in the form of price.
The various sources of public revenue cannot be kept in waterlight compartments. The difference along the various sources of public revenue is in degree and not in kind. For example fees are paid for the Govt. services so also the price. Income from public domain and income from public enterprises are mostly the same. Both public domain and public enterprises are owned, administered and managed by the public authorities. Income from a steel plant is as good as income from a coal mine.