Schema validation covers two distinct use cases: validating JSON data structures against a JSON Schema definition, and validating Schema.org structured data markup (JSON-LD, Microdata, RDFa) embedded in web page HTML.
JSON Schema validation checks that a data object conforms to a defined type contract — required fields are present, data types are correct, and value constraints are met. This is essential for API response validation and data pipeline quality gates.
Schema.org structured data validation checks that pages correctly implement vocabulary types like Product, Article, FAQ, BreadcrumbList, and Event — markup that Google uses to generate rich search results like product carousels, FAQ snippets, and star ratings.