Turnitin is a program that checks student papers against books, journals, Internet sources, and the papers of previous students in order to identify incorrect citations and plagiarism. Metropolitan State University's D2L space uses Turnitin whenever you submit a paper to a dropbox. When you upload a file to D2L dropbox to submit, it is automatically checked by Turnitin.
You may or may not see anything different on your course's D2L page- your professor may or may not choose to hide any Turnitin features, like the Similarity Report.
Turnitin works directly through D2L. When you log in to D2L with your StarID, you can submit a file on your course's "Assignments" page. Once you submit a document into the dropbox, Turnitin automatically checks your paper for improperly cited sources and potential plagiarism.
If your professor has enabled Turnitin icons for your class, you will be able to see the results of Turnitin's Similarity Report, which is what it uses to help your professor identify potential problems with citations in your paper.