A structured data format placed in a webpage's code that explicitly tells search engines and AI systems what a page is about, in a format machines can read directly.
Definition of “JSON-LD”
JSON-LD is a way of writing structured data, using the vocabulary defined by Schema.org, as a small script embedded in a page. It states facts directly: this page is an article, written by this author, published on this date, about this topic, related to these other pages.
Without it, a search engine or AI system has to infer all of this from the visible text and layout of a page, which is slower and more error-prone. JSON-LD removes the guesswork by stating the page's identity and key facts in a standardized format.
“JSON-LD” In Practice
A business adds JSON-LD to its glossary pages that identifies each page as a defined term, links it to the broader glossary, and lists related terms, so that an AI system can recognize the page's purpose immediately rather than parsing it from the surrounding paragraphs.
Worth Knowing
JSON-LD describes a page, it does not improve a page. Adding structured data to a thin or unclear page simply describes that thin, unclear page more precisely. The content still has to be worth describing.