When you log in to your learning environment for the first time, a page will be shown where you can specify what topics you find interesting. The topics that are shown are the categories that have been set in the LMS by the administrators of the academy.
If, as a user, you have chosen one or more topics, you will find them on the discovery page so that you can always find learning items in the library in your area of interest.
You can always change your preferences via the personal settings.