Schema Markup
Schema markup is structured data — a standardized vocabulary from schema.org — added to a page's code to explicitly label what different pieces of content mean (a price, a review rating, a recipe's cook time, an author's name), rather than leaving search engines to infer it from unstructured text.
Updated
November 12, 2026
Category
SEO Glossary
Schema markup doesn't directly change rankings on its own, but it unlocks eligibility for enhanced search result displays (rich results) — star ratings, pricing, event dates, FAQ expansions — that can meaningfully improve click-through rate even without a ranking position change. Beyond traditional search, schema has become increasingly important for AI systems: structured, explicitly labeled facts are exactly what AI Overviews and language models can extract and cite with the most confidence, since it removes ambiguity that unstructured text can carry. Markup must accurately match visible page content — schema describing something not actually present violates Google's guidelines — and the recommended implementation format is JSON-LD rather than the older Microdata or RDFa approaches.
Example
A product page adds Product schema with accurate price, availability, and aggregate review rating, becoming eligible for a rich result showing stars and price directly in the search listing.
Related terms
Related Reading
404 Error
A 404 error is the standard HTTP status code returned when a requested page doesn't exist on the server — the classic 'page not found' response.
A/B Testing (SEO)
A/B testing in SEO is the practice of showing two versions of a page element — usually a title tag, meta description, or on-page element — to see which one earns a better click-through rate or ranking outcome.
AI Citation
An AI citation happens when an AI assistant like ChatGPT, Perplexity, Claude, or Gemini references or links to a specific page as the source for part of its answer.
