Headings provide ‘road signs’ to users as they scan the page. Their direct them to the information they seek.
Frustrating to Users
A page without headings makes it more difficult and frustrating for the user to tell if the page will have information they want or to be able to find it easily.
Search Engines Love Headings
Search engines will use the heading from the page to help determine the subject. This will help search engines deliver the right pages to users in the search result pages.