Labels are an organizing tool that are used to split up a course to make it compact and digestible, within each label there may be lesson sets, assessments, videos, etc. Labels are most often used to split up a course by chapter, learning outcome, or weekly schedule. The photo below shows a course having 4 labels, splitting the material by chapter.
By selecting any of the labels, the content for the corresponding section will appear. To minimize the section, press the label drop-down again.