Semantic Annotation

The process of adding machine-readable metadata to web content that describes the meaning of the content rather than its visual presentation. Unlike HTML markup which primarily specifies how content should be displayed (font size, color, layout), semantic annotations describe what the content represents — for example, identifying that a piece of text is a person's name, a date, a product price, or a geographic location. In accessibility, semantic annotation is closely related to semantic HTML and ARIA: by making content meaning explicit, assistive technologies can better interpret and present information to users with disabilities. Broader semantic annotation using standards like RDF, schema.org, and OWL enables even richer content understanding, supporting automatic content adaptation, intelligent search, and personalized information delivery.