Heading structure (H1-H6)
The hierarchy of HTML heading elements that conveys a document's outline to users, assistive technology and parsers.
TechnicalSemantic markup
Semantic HTML
Using HTML elements according to their meaning — article, nav, main, table, time — rather than generic divs styled to look right.
In full
Semantic elements give parsers reliable structural cues: `<main>` and `<article>` help isolate primary content from boilerplate, real `<table>` markup preserves relationships that a div grid destroys, and `<a href>` is the only link form crawlers follow. This matters more as content is consumed by extraction pipelines that must decide which part of a page answers a question. It is also the foundation of accessibility.
Example
Replacing `<div onclick="navigate()">` navigation with real anchors makes 200 previously undiscoverable category pages crawlable.
Related terms
DOM (Document Object Model)
The in-memory tree representation of a document that the browser builds from HTML and mutates with JavaScript; the rendered DOM is what…
Progressive enhancement
A build strategy that starts with working HTML and layers on CSS and JavaScript, so core content and navigation function without scripts.
Internal linking
Links between pages on the same site, which control crawl paths, distribute link equity, and communicate topical relationships and page…
Semantic chunking
Splitting documents along meaning boundaries — sections, topics, complete ideas — rather than at fixed character counts, to produce…
Where to read more
- Web Content Accessibility Guidelines (WCAG) 2.2 · Standard · w3.org