What is the difference between a heading hierarchical headings and subheadings?

Subheadings are more specific than headings. When a member shares a new resource, she is asked to tag it with subheadings if possible.

• A resource will be tagged with a heading if it fits that general category but does not fit under any of the specific subheadings.
• A resource will also be tagged with the heading instead of a subheading if it fits under all of the subheadings.