Books and periodicals refer to books and publications. Newspapers are printed publications, which mainly publish news and current affairs comments and are distributed to the public on a regular basis. It is an important carrier of mass communication and has the function of reflecting and guiding public opinion. A magazine, with a fixed title, is a kind of printed reading material published regularly or irregularly, with expectations, number of volumes or chronological order. According to a certain editing policy, it collects the works of many authors and publishes them in a book, which is also called a periodical.