Make it clear what the site is, in a form machines can read.

Google describes structured data as a standardised format for giving information about a page and classifying its content. Most of it uses the schema.org vocabulary, but Google says to treat its own Search Central documentation as definitive for Google Search behaviour, because schema.org contains more types and properties than Google uses. Google supports JSON-LD, Microdata and RDFa, and recommends JSON-LD.

Design is mostly about fit. Google's general guidelines say the markup must describe the page it is on, must not mark up content users cannot see, and should use the most specific applicable schema.org type. Required properties for a feature must be present or the page is not eligible for that rich result. Where a page holds several related items, such as a recipe and its video, Google says to link them with @id so it can tell they belong together. Our Web Development page states the same intent: structured data designed with the content model.

Validation has limits. Google points to the Rich Results Test and the URL Inspection tool, which catch most technical errors, but says that correct markup does not guarantee a rich result. Structured data enables a feature; it does not promise one. Structured data that breaks the guidelines can also lead to a manual action, which Google says removes rich result eligibility without affecting web ranking.

We cover schema design and validation as part of our structured data work in Technical SEO.

An entity here means a distinct thing such as a business, a person or a product, as opposed to a string of words. Google says it uses structured data to understand the content of a page, and also to gather information about the web and the world in general, such as the people, books or companies included in markup.

Google's Organization documentation is the clearest example of this. Organization markup on a home page can help Google understand an organisation's administrative details and disambiguate it from other organisations in search results. Some properties, such as the logo, can influence what is shown in results and in a knowledge panel. No properties are required; Google recommends adding as many relevant ones as apply. Its own example includes sameAs links to profiles elsewhere, and contact and address details.

The consistency requirement from the general guidelines applies here as well. The markup has to match what the page visibly says, and has to be true. The same facts, stated the same way in markup and on the page, are what make an entity clear rather than ambiguous.

Google's pages cover Google Search. They do not describe how other AI tools identify entities, and we do not claim they do.

We cover entity understanding as part of our structured data and entities work in Technical SEO. The AI search side is on the Machine understanding page.

Structured data is one of several machine-readable layers on a site. The others are files and signals Google documents separately: sitemaps, which list URLs and, through lastmod, when they last changed significantly; and robots.txt, which tells crawlers which URLs they may access. Google says it uses lastmod only if the value is consistently and verifiably accurate. It also warns that robots.txt is not a way to keep a page out of Google.

These layers interact. Google's guidelines say not to block pages carrying structured data with robots.txt, noindex or other access controls, and that image URLs in structured data must be crawlable and indexable. Markup that Googlebot cannot reach does nothing.

Google is also direct about what you do not need. Its AI features guidance says you do not need to create new machine-readable files, AI text files or markup to appear in AI Overviews or AI Mode, and that there is no special schema.org structured data to add. The useful work is accurate, crawlable, consistent information, not a new file format.

Our own home page shows illustrative markup under the heading "What the site tells machines", as a reminder that these signals are written for crawlers and answer engines as well as people.

We cover machine-readable site information as part of our structured data and entities work in Technical SEO.

Google's AI features guidance says the best practices for SEO remain relevant for AI Overviews and AI Mode: There are no additional requirements to appear in AI Overviews or AI Mode. To be shown as a supporting link, a page must be indexed and eligible to appear in Google Search with a snippet. The guidance lists fundamentals that still apply, including allowing crawling, internal links, important content in text, and structured data that matches the visible text.

That is the connection. Structured data and clear entities do not create a separate route into AI answers on Google; they are part of the same technical foundation as everything else. If a page is not crawlable and indexable, markup on it cannot help. Google also says AI feature traffic is reported in Search Console's Performance report under the Web search type.

The scope is Google's. ChatGPT, Gemini and Perplexity are described on our AI & Search Visibility page, which states that entities and structured data feed answer engines and that there is no trick to appearing in them. What each system does with markup is not something Google's documentation can tell you, and we say so rather than guess.

We cover how structured data and entities feed AI search visibility as part of Technical SEO, and the wider work sits on AI & Search Visibility.