The Zoning Board of Adjustment, also referred to as the Board of Apppeals, is required by RSA 673:1 and is mandatory whenever a town or city enacts a Zoning Ordinance. As a "quasi-judicial" entity, the main goal of the ZBA is to make exceptions to the ordinance without having to change the ordinance itself (something only the Town Council has that authority to do). Under State enabling statutes (RSA 674:33), the ZBA has the authority to act in four separate and distinctive categories whenever a property owner seeks relief from the requirements of Londonderry's zoning ordinance: