New York City encompasses five different county-level administrative divisions called boroughs: Manhattan, the Bronx, Queens, Brooklyn, and Staten Island. Each of the boroughs is coextensive with a respective county, the primary administrative subdivision within New York State.
Boroughs have existed since the consolidation of the city in 1898, when the city and each borough assumed their current boundaries. However, the boroughs have not always been coextensive with their respective counties. Before 1914, the borough of The Bronx had been earlier in the southern part of Westchester County which had then been annexed to New York County in two stages in 1874 and 1895 -- finally, in 1914 the county was created to match the borough. Before 1899, the County of Queens included a western part, which was split-off during the consolidation to become Nassau County.
The term borough was adopted to describe a form of governmental administration for each of the five fundamental constituent parts of the newly consolidated city in 1898. Under the 1898 City Charter adopted by the New York State Legislature, a "borough" is a municipal corporation that is created when a county is merged with populated areas within it. The limited powers of the borough governments are inferior to the authority of the Government of New York City, contrasting significantly with other borough administrations of government used in Connecticut, New Jersey, and Pennsylvania, where a borough is an independent level of government, as well as borough forms used in other states and in Greater London.