Glossary
Schema markup (JSON-LD)
Schema markup is structured data — usually JSON-LD — embedded in a webpage to tell search engines and AI systems exactly what the page is about.
Schema markup uses the schema.org vocabulary to describe entities on a page: an Organization, a Product, an Article, a FAQ, a recipe, a job posting. Modern sites embed it as JSON-LD inside a <script type='application/ld+json'> tag.
Schema markup powers Google's rich results (FAQ accordions, recipe cards, star ratings, breadcrumbs, course panels, event panels) and helps LLMs like ChatGPT and Perplexity understand and quote your content accurately. The rich-result yield depends on the schema type — FAQ accordions historically had the highest rich-result rate, though Google has dialed that back.
Common types: Organization (the company), WebSite (the site itself), SoftwareApplication (a software product), Article (a blog post), FAQPage (FAQ sections), BreadcrumbList (navigation hierarchy), Product (an e-commerce item), LocalBusiness (a brick-and-mortar business), Person (a creator or expert), Event (a conference / meetup), Course (a class or program).
Schema is policy-sensitive. Fabricated AggregateRating (review schema with invented numbers) can trigger Google manual actions and is a fast way to lose rankings. The rule is simple: only mark up what's actually on the page, only claim what's actually true. Fake ratings are the most common violation; missing 'mainEntityOfPage' on Article markup is the second.
Validation: Google's Rich Results Test (search.google.com/test/rich-results) checks if a page qualifies for a specific rich result. Schema.org's validator checks generic structural correctness. Most modern AI builders include schema generation by default — but the entity claims (ratings, prices, addresses) need to be accurate to the actual page content.
Example
Adding FAQPage schema to a comparison page used to mean Google might render a stacked accordion of 6 questions visible directly in search results. Google's policy on FAQ rich results changed in 2023 (most FAQ rich results now require domain authority), but the schema still helps LLM search and Google's understanding of the page.