Short and sweet:
Structured data; a standardized format for labeling information on a webpage, like product prices, reviews, or article authors, so search engines and AI systems can read and interpret it more reliably than plain text.
Implemented most commonly through schema markup, a specific vocabulary of structured data tags.
See also: Schema Markup, SEO, AEO
Structured data works like a translation layer between a webpage and the machines reading it, explicitly tagging pieces of information, this is a price, this is a review rating, this is a publish date, rather than leaving a search engine or AI model to guess at meaning from surrounding text. Common uses include:
As AI-driven search has grown, structured data has taken on added importance, since a clearly tagged fact is easier for a language model to extract and cite accurately than the same fact written in unstructured prose.
An e-commerce site might add structured data to its product pages so prices and star ratings show up directly in Google’s search results.
A recipe blog could tag its ingredient list and cook time with structured data, making it eligible for a recipe-specific rich result.
A glossary page like this one might use structured data to mark each term as a definition, making it easier for AI answer engines to cite it accurately.
