Keyword is a new vocabulary of information retrieval language, which is used to describe the theme of literature and give information retrieval. It is precisely because of its appearance and development that it is possible to computerize information retrieval (computer retrieval). Keywords refer to words or phrases that distinguish things through the characteristic relationship of concepts, express them in natural language, and have collocation function to accurately express the dynamic semantic conceptual relationship between words.
Keywords are keywords that mark the subject content of document construction, but have not been standardized. Keywords are words or terms selected from papers for document indexing to express the main contents and information items of the full text. A paper can choose 3~8 words as keywords.