ELMS is built on top of Drupal.  In the Drupal community, ELMS is known as a distribution of Drupal.  One of the major goals of ELMS is to remove the barrier that Drupal creates in terms of knowledge to use the platform. This provides site builders and developers with the most powerful framework while framing everything in an educational context for end-users.

If you need to administer Drupal, such as activating modules, or changing system settings; click the wrench at the bottom left corner of any page.  ELMS uses a project called Admin which provides this functionality and simplified the user experience for developers and site builders.  Click Administer, then Site Building, then Modules in order to activate / disable modules.

To change specific system wide settings you can go to Site Configuration under Administer and alter any settings that Drupal provides.  Drupal and ELMS are both extremely modular so if you have questions about how to add or safely modify functionality just ask in the ELMS issue queue on Drupal.org