What's the difference between teacher D recruitment and abc exam?

The written examination of public subjects in the open recruitment examination of public institutions is divided into five categories: comprehensive management (Class A), social science expertise (Class B), natural science expertise (Class C), primary and secondary school teachers (Class D), and medical and health care (Class E). In principle, the examination category corresponding to the recruitment position is determined and marked in the recruitment announcement, and the applicants take the written examination of public subjects according to the examination category. Among them, the category of primary and secondary school teachers (category D) is mainly suitable for teaching posts in primary and secondary schools, technical secondary schools and other educational institutions.