Home rule in the United States relates to the authority of a constituent part of a U.S. state to exercise powers of governance (i.e., whether such powers must be specifically delegated to it by the state—typically by legislative action—or are generally implicitly allowed unless specifically denied by state-level action). Forty of the fifty states apply some form of the principle known as Dillon's Rule, which says that local governments may exercise only powers that the state specifically grants to them, to determine the bounds of a municipal government's legal authority.
In some states, known as home rule states, the state's constitution grants municipalities and/or counties the ability to pass various types of laws to govern themselves (so long as the laws do not conflict with the state and federal constitutions). In other states, known as Dillon's Rule states, only limited authority has been granted to local governments by passage of statutes in the state legislature. In these states, a city or county must obtain permission from the state legislature if it wishes to pass a law or ordinance not specifically permitted under existing state legislation. Most states have a mix; for example, allowing home rule for municipalities with a minimum number of residents.
