Schema.org

Schema.org is a collaborative, community-developed vocabulary of types and properties for describing entities, relationships, and actions in structured data. It was founded by Google, Microsoft, Yahoo, and Yandex and now evolves through its community and steering processes. The vocabulary can be expressed in formats such as JSON-LD, Microdata, or RDFa and can be used on web pages, in email, and in other data exchanges.

Why it matters: First identify the entity and facts the page visibly communicates, then choose the most specific applicable Schema.org types and properties. Schema.org defines the vocabulary; JSON-LD, Microdata, and RDFa are encodings, and a consumer such as Google defines which subset, required fields, policies, and experiences it supports. Keep values complete, current, non-misleading, and consistent with visible content and canonical identifiers. Validate vocabulary usage with Schema Markup Validator, and use a consumer-specific test and documentation for the feature you expect. Valid Schema.org data can improve machine understanding, but it does not make every property useful to every consumer or guarantee crawling, indexing, a rich result, ranking, or traffic.