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. It has the functions of preserving human cultural heritage, developing information resources and participating in social education. Another function is to collect resources that people don't want to buy and provide them for the public to use or consult. It can be run by public organizations, government agencies or private organizations.

Library is a kind of social memory, which is usually manifested as the external storage and selective transmission mechanism of written records. In other words, the library is the memory device and diffusion device of social knowledge, information and culture.