Schema.org defines how structured data is named. The vocabulary defines types such as Article, Product, Organization or Person and their properties, for example author, price or address. According to Schema.org, release 30.1 from September 2026 contains 826 types and 1,540 properties.
An example: an online shop marks up a product page with the Product type and adds price and availability via the Offer type.
Schema.org lists Google, Microsoft, Yahoo and Yandex as its founders. Since 2015, development has taken place openly in a W3C Community Group.
Websites usually embed the vocabulary as JSON-LD, or alternatively as Microdata or RDFa. Google recommends JSON-LD in most cases. Google uses Schema.org markup to understand pages and to show rich results. According to Google, no special markup is needed for AI Overviews.
How to use Schema.org for Google and AI search is explained in our article on structured data for Google and AI search.