What are keywords? As the name suggests, keywords are critical words. From a linguistic perspective, keywords are the words that can describe the essence of an article. In the field of information retrieval, keywords are understood as the nouns or phrases that represent the substantive meaning of a document, which often appear in the title or the main text of a document. Each document should have keywords to determine its theme and distinguish it from other documents, which helps with document retrieval, inquiry, and facilitates the exchange and transmission of information.