Structured data
Structured data is markup that describes the meaning of information on a page. It lets you state unambiguously that a piece of content is about an organization, a product, an offer or another type of thing.
Schema.org and JSON-LD
Schema.org is a vocabulary of types and properties, such as Organization or Product. JSON-LD is one way of writing that information into a page’s code. They are not two names for the same thing.
What is worth marking up
Markup should match the visible content and your actual offer. You choose the type based on what a specific page contains.
Valid markup alone doesn’t guarantee a citation. Google doesn’t require any special schema for its AI features. Nor does missing markup mean a model can’t read plain text.
Why consistency with visible content matters most
Markup that states a different price, availability or company name than the text customers see sends a contradictory message. It can also go out of date when your offer changes, even if the page itself was updated. A good practice is to feed the visible content and the markup from the same data source. Before deploying, check not just the syntax but whether the values match reality.
Fit the markup to the specific page. An article, a product and an organization page describe different things. Adding every available type doesn’t make the data more useful. In a glossary, a definition can be marked up as a DefinedTerm and the navigation path as a BreadcrumbList. That names a structure that already exists; it doesn’t replace clear headings, content and ordinary links.
For breadcrumbs, names and URLs should reflect the real hierarchy. A path like “Home → Glossary → term” describes where an article sits on the site. Don’t add levels that don’t exist or point items to random pages with similar names.
Common mistake: adding properties you can’t back up
Don’t invent customer ratings, awards or product specs just to fill in a schema. Markup should present facts, not a wishful picture of your offer. Technically valid markup can still describe wrong information. After publishing, check the result with a validation tool and compare it with what users actually see. Passing validation doesn’t promise a rich result or an AI citation.
Example
A product page shows the product’s name, price and availability. Structured data can describe the same information as properties of the product and its offer.
Key takeaway
Get your content true and readable first. Markup supplements it; it doesn’t replace it.