Nanjing Library is open from 9: 00 am to 7: 30 pm every Tuesday to Sunday/kloc-0. Nanjing Library is an important public cultural service facility in Nanjing, which provides readers with rich collection resources and comfortable reading environment. The specific opening hours of each service window are slightly different. For example, the children's library (7- 15 years old) is open from Tuesday to Friday 12: 30 to 17: 30, winter and summer vacations, weekends and weekends. The library is a cultural and educational institution that specializes in collecting, sorting, preserving and disseminating literature information and providing lending services to the public. The main functions of the library include the collection, arrangement, storage and service of literature information, and also play the role of education and cultural communication. There are many types of libraries, which can be classified according to the service objects, collection characteristics and scale. Common types are public library, school library and professional library. Public libraries are open to the public and provide a variety of books and information services; The school library mainly provides teaching and research materials for teachers and students; Professional libraries focus on literature collection and research in a certain subject or field. The operation and management of the library follow certain principles and norms, including collection construction, classification and cataloging, lending service, etc. Among them, collection construction refers to the process of collecting and sorting out various literature resources in a planned way according to the library's own positioning and service objects. Classification and cataloging is to classify, catalogue and index the collected documents according to certain rules and standards for easy retrieval and utilization. Lending service is a process in which the library provides readers with services such as book lending, reading and information consultation.