Counties serve as the primary second-level administrative division in the United States, with 3,143 counties functioning as intermediaries between state and municipal governments. These subdivisions typically administer essential services including law enforcement through sheriffs' departments, judicial systems through county courts, property assessment and taxation, vital records maintenance, elections administration, and public works such as roads and bridges. Counties also frequently manage public health services, land use planning, and social services programs. The scope of county authority varies considerably by state, with some states granting counties broad home rule powers while others maintain strict state control over county functions. In Louisiana, equivalent divisions are called parishes, while Alaska uses boroughs for similar purposes. County governments generally operate through an elected board of commissioners or supervisors, though organizational structures differ based on state constitutional provisions and local charters.