1, different job applicability.

Class A is a comprehensive management class: suitable for posts focusing on administration, affairs and business management; Class B is a social science major: suitable for general social science researchers and art majors; Class C is a natural science major: suitable for general natural science researchers.

2. The content of the exam is different.

Class A is an examination subject set for public institutions to openly recruit management staff; Class B is an examination subject set for public institutions to openly recruit professional and technical staff in humanities and social sciences; Class C is an examination subject for open recruitment of staff for natural science professional and technical posts in public institutions.

Brief introduction of public institutions:

Refers to the social service organizations established by the government with state-owned assets and engaged in education, science and technology, culture, health and other activities. It is a non-profit organization. Institutions accept the leadership of the government and are legal entities in the form of organizations or institutions. The obvious characteristics of public institutions are the suffix of center, meeting, institute, station, team and hospital, which are divided into public institutions and general public institutions.

Institutions refer to social service organizations organized by state organs or other organizations with the purpose of social welfare and engaged in education, science and technology, culture, health and other activities.

Under the leadership of the state administrative organs, there is no production income, the required funds are paid by public finance, and economic accounting is not implemented, mainly providing intangible production and labor services for education, science and technology, culture, health and other activities. Institutions accept the leadership of the government and are legal entities in the form of organizations or institutions.