The results may vary between Plagiarism Checker X and Turnitin because the two tools use different databases and algorithms for comparison. Turnitin has access to a much larger academic database, including student papers, journals, and books, which might flag additional sources that Plagiarism Checker X may not detect. Therefore, while Plagiarism Checker X can give you a basic idea of your document’s originality, your teacher’s check using Turnitin may yield different (and potentially higher) plagiarism results.