Search Engine Land's Guide to SEO Chapter 3: HTML Code & Search Engine Ranking Success Factors explains HTML elements & using structured data.

Google's John Mueller advises using semantic HTML. Though not a ranking factor, it helps search engines understand content and boosts accessibility.

Semantic HTML makes it clear where the main content of a webpage is, which can be helpful for search engines and accessibility ...

Learn instances where using visual, HTML sitemaps make sense than simply relying on your website's navigational structure or XML sitemaps.

In fact, HTML is the most significant computing language ever developed. Underestimate it at your peril.