A zoning ordinance is the formal codification of land use policies for a city, district, county, or other unit of government. The goal of a zoning ordinance is to establish permitted uses for land covered by the ordinance, and to distinguish between different types of uses which may be incompatible. In addition to defining specific types of land use, zoning ordinances also usually divide a region into "zones" where certain types of permitted use can occur, which explains the name.
Most zoning ordinances include three basic types of zoning districts:
There are a variety of more specialized types of zones - office and institutional, flood hazard, mobile home park, agricultural, and perhaps planned unit development. There may be a number of residential districts, each based on different permissible dwelling types and required lot sizes (or densities). Municipal Government in North Carolina - David M. Lawrence and Warren Jake Wicker.