Complex sentence: Outlines present their content as subheadings and list entries: an outline article breaks its subject down into a taxonomy in which the levels are represented by list entry indentation, subheading levels, or both.
Split into simpler sentences: Outlines present their content as subheadings and list entries. An outline article breaks its subject down into a taxonomy in which the levels are represented by list entry indentation, subheading levels, or both.