The paper duplication checking system is usually compared with the documents in a large database to detect whether the content of the paper is similar or the same as other documents. The database may contain many academic publications, periodicals, conference papers, etc. , but not limited to these.

The paper adopts fuzzy algorithm in duplicate checking system. If the overall structure of the paper is disturbed, it may lead to different duplicate checking results. At the same time, when the paper is detected by the duplicate checking system, it will be compared with the online database search, so the data compared in the paper is not limited to the database of the duplicate checking system. Therefore, it is suggested that footnotes or endnotes should be used as much as possible when quoting literature.

Different duplicate checking systems may have some differences in comparison methods and data sources, so it is necessary to know their comparison methods and detailed information according to specific duplicate checking systems.