Structured data, explained
Structured data is a way of describing a page's content so machines do not have to infer it. Using the shared schema.org vocabulary, usually written as JSON-LD in the page's code, a site can state plainly that it represents an organization with a given name, address and logo; that a page is an article with a particular author and date; that a service is offered in a defined area; or that a section contains questions and answers.
Search engines use structured data to understand pages and entities, and to qualify pages for certain rich results. It also helps connect a site to its official profiles elsewhere, which supports entity SEO. Other systems that read the web, including some AI tools, can use the same information.
It is important to be clear about limits. Structured data must match what is visible on the page, and markup that misrepresents content can lead to manual action. Google has said there is no special structured data required to appear in its AI features such as AI Overviews. Schema is good hygiene and a clear statement of facts; it is not a ranking shortcut or a guarantee of AI citations. Accurate, complete markup on a well-built site is the goal.