1. According to the publishing form, it can be divided into ten categories: sci-tech books, sci-tech periodicals, patent documents, conference documents, sci-tech reports, government publications, dissertations, standard documents, product materials and other documents.

2. According to the processing depth, there are primary documents, secondary documents and tertiary documents.

Characteristics of literature

(1) knowledge. Literature refers to all carriers with knowledge, and the content of knowledge information is the core and soul of literature, so knowledge is the essential feature of literature.

(2) transitivity. Literature appears and exists as a tool for spreading knowledge and information, and human knowledge wealth can only be spread through literature. Literature can not only make human knowledge handed down from generation to generation, but also make human knowledge communicate and pass on among different countries, nationalities and regions. Therefore, transmitting knowledge and information is the basic function of literature.

(3) Material carrier. Only when it is recorded on the material carrier in the form of symbols can it be preserved and spread.

(4) Manual recording. The knowledge information contained in the literature is recorded on the carrier in various ways.

(5) Reproducibility and accumulation. In the process of using literature information, people produce new literature information at the same time, so the amount of literature information is increasing. Although some literature information is gradually aging with the development of the times, due to people's constant demand for literature information, there are a lot of regeneration phenomena, so literature information is always in the process of accumulation and appreciation.