A heading is a text element that provides a title or headline for a section of content on a webpage. These elements guide users and search engines through your content.
Since headings typically use larger, bolder font sizes than the surrounding text, they make reading the page easier. Headings also play an essential role in search engine optimization (SEO), as search engines use them to understand the structure and hierarchy of a webpage's content.
The six levels of headings in HTML indicate the relative importance of the content within the section, from H1, the most important, like a newspaper headline, to H6, the least important. You’ll use an H1 for the page’s main title and H2 – H6 for subheadings and subsections.
Many webpages have at least one H1, H2, and H3. You’ll only use one H1 per page, but you might use multiple H2s for sections that are all equally important. The heading for a subsection of an H2 would be H3.