Semantic HTML

Using HTML tags that describe their meaning — like labeling boxes 'kitchen' and 'bedroom' instead of just 'box 1' and 'box 2.'

Choosing HTML elements (<article>, <nav>, <header>, <main>) that convey structural meaning to browsers, search engines, and assistive technologies rather than relying on generic <div> and <span> elements.

Semantic elements map to ARIA landmark roles implicitly (e.g., <nav> → role='navigation'), reducing the need for explicit ARIA attributes. The HTML Accessibility API Mappings spec defines how each element is exposed to the accessibility tree, making correct element choice the single highest-impact accessibility decision.