What is Structured Data?
Machine-readable markup that describes a page's meaning to search engines and other consumers.
Definition
Structured data annotates page content with an explicit vocabulary—overwhelmingly schema.org—so a crawler can tell that a number is a price, a rating, or an event date rather than guessing from position. JSON-LD embedded in a `<script type="application/ld+json">` block is the format Google recommends, since it sits apart from the visual markup and survives redesigns that would break inline microdata or RDFa. Correct markup makes a page eligible for rich results: review stars, FAQ accordions, breadcrumb trails, product pricing, and article bylines. Eligibility is not a guarantee, and markup that describes content not visible on the page is a manual-action risk. Google's Rich Results Test and Search Console's enhancement reports are the standard validation path, and the same annotations increasingly help LLM-based answer engines parse a page.