Library web pages can be divided into those that have been purchased and authorized for use and those that have not been purchased but provided by database providers. A library is an institution that collects, sorts out and collects books and materials for people to read and refer to. The resources of the library's webpage data repository are divided into two categories:

1, a database that has been purchased and authorized for use, or provided free of charge by relevant institutions, that is, "library digital resources" in the library website;

2. A database that has not been purchased but is provided by a database provider and has a limited free use period, that is, the "trial digital resources" in the library webpage.