According to relevant information, the number of people in circulation in a library refers to the total number of readers who use the library in a certain period, including all the services of borrowing library books, so even the out-of-office services of the library are included, because the books in the library are also used in this period.

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.