Article 1 calls India a “Union of States”, not a federation, and the rest of the Constitution explains why: power is divided between the Union and the States, but the division leans towards the Centre. This chapter covers how that division works in practice and where it rubs.

What UPSC asks

Prelims tests exact articles: Articles 249, 252 and 253 (Parliament legislating on State subjects), Article 263 (Inter-State Council), Articles 270, 275 and 282 (devolution and grants), Article 279A (GST Council), and the 42nd Amendment’s transfer of subjects to the Concurrent List.
Mains GS II asks about cooperative and competitive federalism, the Governor’s role, Article 356 after S.R. Bommai, fiscal federalism after GST, and inter-State disputes.

Key sub-topics

Sub-topic	Core provisions
Nature of Indian federalism	Article 1; federal and unitary features
Legislative relations	Articles 245–255; Seventh Schedule
Administrative relations	Articles 256–263; Article 365
Financial relations	Articles 264–293; Article 279A
Emergency and President’s Rule	Articles 352, 356, 360
Reform commissions	Sarkaria (1983), Punchhi (2007)

Start with the main note, Centre-State Relations, then revise with the quick revision sheet and test yourself on the practice questions.