Centralized management and decentralized use. According to the relevant information of the three types of books in the school library, the three types of books in the school library refer to centralized management and decentralized use. A library is an institution that collects, sorts out and collects books and materials for people to read and refer to. As early as 3000 BC, libraries appeared. Library has the functions of preserving human cultural heritage, developing information resources and participating in social education.