Semantic HTML makes it clear to search engines exactly where the content you want to be indexed is on a webpage, which is why it should be considered for both SEO and website accessibility.

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

Semantic HTML5 provides us with an opportunity to improve our websites and optimize for search engines. We can take full advantage of these opportunities by using machine-readable semantic HTML5 ...

“Making standards is hard work,” writes Tim Berners-Lee in a recent blog post. And he should know. The creator of the World Wide Web, Berners-Lee is responsible for developing and popularizing ...

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