§ 1980. Definitions. When used in this article, the following terms shall mean: 1. The term "board of education" shall mean the trustee, trustees or board of education of any common, union free, central, central high or city school district, or a board of cooperative educational services. 2. The term "school district" shall mean any common, union free, central, central high or city school district, or a board of cooperative educational services. 3. The term "district superintendent" shall mean the chief administrative officer of a supervisory district as defined in article forty-five of this chapter.