TurnitinUK is an online text matching service which helps staff in detecting possible plagiarism.  Turnitin enables Institutions to compare students work with an extensive database of electronic sources. 

Along with Turnitin is Feedback Studio which is an online marking tool.  Students must submit work via a TurnitinUK assignment.  After submission the instructor has the option to use the plagiarism detection tool and/or use Feedback Studio for marking purposes.

More info on Feedback Studio