Semantic Structure

Semantic structure refers to the meaningful organisation of content that captures the conceptual relationships between pieces of information, as distinct from the syntactic or visual presentation of that content. In web accessibility, semantic structure is critical because assistive technologies like screen readers rely on it to convey the meaning and relationships within documents. For example, an HTML table may have a visual two-dimensional layout, but its semantic structure might be three-dimensional (e.g., city x date x expense category), and this conceptual organisation is what needs to be communicated to non-visual users. Semantic HTML elements (headings, lists, tables with proper headers, landmark regions) provide the foundation for conveying semantic structure, but complex content may require additional annotation beyond what HTML markup alone can express.