A Prerequisite refers to the lessons you need to complete before you can move on to the next set of Lessons.
On Wheelhouse College, your prerequisites are the level previous to the one you're looking at. For instance, the Sales Manager Level 3 training has a prerequisite: Sales Manager Level 2 training.
A staff user can view the pre-requisite of their currently selected course in the Course Details panel. Managers and admin can view the pre-requisites of courses in the Library and Your Courses tabs by selecting the course title.
Staff User - Your Courses - Pre
Admin/Manager - Library - Course Pre-requisites
Admin/Manager - Your Courses - Course Pre-requisites