i know this website write-check his functionality is uploading a file(PDF,Doc) and check percentage of redundancy between the file uploaded and a lot of websites ,books,researches and after user upload file and result shows that result show redundancy percentage and highlight on copied paragraphs . that paragraphs were repeated in website references when user hover on these highlights the source or references appear to the user to make sure the source he copied from this is explain simply for website functionality can any one help me in analysis for asp.net website has the same functionality and how check between uploaded file and archived files