Cleaning agent, cleaning ball, etc. Books are welfare products such as detergent and cleaning balls for live broadcast. Book is a collection concept evolved from book. Ancient books refer to maps, decrees, household registration and other literature classics, which mainly exist in the form of calligraphy, rubbings, thread-binding, etc. Modern books refer to books, periodicals, newspapers, pictures and other published printed materials; Modern books generally refer to all kinds of knowledge carriers, including books and periodicals, printed matter, manuscripts, microforms, audio-visual materials, computer tapes, disk materials and so on.