states

States are political subnational units in federations or quasi-federal systems. They have defined borders and governmental authority granted by a constitution or legal framework. A state typically operates with its own executive, legislature, and judiciary, and may enact laws on matters within its competence, such as education, policing, health, infrastructure, and local taxation. In federal systems, states may negotiate with the central government and may have representation in the national upper chamber (for example, the United States Senate represents the states; other countries vary). The degree of autonomy and the division of powers between state and national authorities differ by country and constitution, ranging from highly decentralized federations to more centralized arrangements in unitary states with strong regional authorities.

Examples illustrate the range: the United States comprises 50 states with substantial concurrent and residual powers; Germany consists of 16 states called Länder with significant own lawmaking power; India has states and union territories, with states enjoying substantial legislative autonomy under the constitution. In unitary states, subnational units exist largely to administer centralized policy and may have limited independent authority. The term "state" also appears in other contexts, notably in physics where it denotes a condition of matter (solid, liquid, gas, plasma) and in political theory referring to the organized government and its apparatus.

In practice, the status and powers of states are defined by national constitutions, statutory law, and, in many cases, by judicial interpretation. The concept remains central to discussions of sovereignty, federalism, and governance.