Resources are one way to offer supplementary content to your learners. Resources can be uploaded either as a Global Resource or as a Course Resource and these two methods will impact who has access to this resource.
Course resources can be added in the "Resources" tab in any online course, instructor led course, or curriculum.
These resources will be displayed on the right-hand side of the course page in the learner interface, and will ONLY be available to learners that have been enrolled in the course.
Global resources can be added in the "Global Resources" report.
These resources will be displayed in your learner interface's "Resources" page which can accessed via optional dashboard. These resources are also searchable in the learner interface.
By default, Global Resources are visible to all logged in users in your LMS, but availability rules can be set up to filter on different learner fields to include/exclude certain groups of users from seeing them.