Explanation:

Union list

Taxes and revenues in India are collected both at Central and State level as well as at local levels. For this purpose, the seventh schedule of Indian Constitution has divided taxable subjects into Union List where Parliament can make laws , State List where State legislature has power to make rules and Concurrent List where both Centre and State has the power but in case of conflict Centre's rule prevails. As per the seventh schedule, railways is a subject of the List I or Union List as entry 22.