HTML headings help show search engines which text is important on a site’s webpages, giving certain titles authority. These headings are ranked in a hierarchy – between <H1> and <H6> – which denotes their level of importance. H1 tags are used for headlines and titles, and then the tags cascade down for sections and subsections.
SEO experts use HTML headings to feature prominent keywords, as they’re picked up by search engine ranking systems. It’s regarded as especially important to include a keyword in every H1 tag, as this is the most important text on your website from a ranking perspective.