These are most commonly used as subheaders, with Header 2 denoting a more specific topic than Header 1, and Header 3 being more specific than Header 2.
Subheaders like Header 2 and Header 3 also prioritize text to search engines, although to a lesser degree. These are most commonly used as subheaders, with Header 2 denoting a more specific topic than Header 1, and Header 3 being more specific than Header 2. Employ a mix of header types to both make your content more skimmable for readers and to clearly share the focus of your pages with search engines.