Semantic HTML.

Semantic HTML is the practice of using HTML elements for their intended purpose and meaning rather than purely for visual styling. Elements like <h1>–<h6> (headings), <article>, <section>, <nav>, <aside>, <header>, <footer>, <main>, and <figure> communicate the structural role of content to browsers, screen readers, and search engine crawlers — not just its visual appearance.

Why Semantic HTML Matters for SEO

Search engines parse HTML to understand content hierarchy and context. A properly nested heading structure (h1 → h2 → h3) signals topic hierarchy, helping Google understand which part of a page covers which subtopic. The <article> element identifies the primary content block; <nav> marks navigation; <aside> flags tangential content. Using <div> for everything forces crawlers to infer structure from context, reducing parsing accuracy.

Semantic HTML and Accessibility

Accessible websites and well-crawled websites largely share the same requirements: logical heading hierarchy, image alt text, descriptive link text, properly labelled form elements. Screen readers and crawlers both rely on semantic structure to understand content. Accessibility SEO is a genuine correlation — sites built accessibly tend to be better indexed. Using semantic HTML, ARIA labels, and structured data in combination produces the clearest possible signal of content purpose.