A business improvement district (BID) is a defined area within which businesses pay an additional tax or fee in order to fund improvements within the district's boundaries. BIDs may go by other names, such as business improvement area, business revitalization zone, community improvement district, special services area, or special improvement district. BIDs provide services, such as cleaning streets, providing security, making capital improvements, and marketing the area. The services provided by BIDs are supplemental to those already provided by the municipality.