It is the organization by order of relevance of the different titles of a content thanks to HTML tags. There are 6 hn tags (the H stands for "Heading"), from H1 to H6 (where H1 indicates the most important title and H6 the least important).
The structuring of hn headings is important, because it helps the indexing and referencing of your page. The hierarchy of titles and subtitles makes it easier for search engines to understand your content by highlighting its important elements. This structuring also improves the experience of the users who find and understand your content more easily.
To be able to structure hn tags, it is necessary to respect the hierarchy of these titles: their order and size. The recommended structure is therefore, (for example) :
<h1>Heading structure</h1> <h2>Why is heading structure important?</h2> <h2>How to structure your content</h2> <h3>Example of a heading structure</h3> <h3>Some tips to structure your content by relevance</h3> <h2>...</h2>
To succeed in structuring your hn tags, it is necessary to :