Purpose of the Schema and Schema Validator
The World Wide Web has evolved since its inception as, Web 1.0 - first stage of the World Wide Web roughly 1991 to 2004. Most of the WWW users use the content from the web (from static websites)
Web 2.0 is the participatory content or social web. It refers to the User generated content including social sites, interoperability between devices
Semantic Web or Web 3.0 - This is the next version of web that uses Knowledge graph technique to read internet data in a machine readable format.
All the entities, objects, persons, relations of the real world are coded as nodes and connected through edges of knowledge graph.
Rich Snippets/ Schemas
To represent any real world objects, persons, entities, products, offers, availability, offers, movie information, etc., on internet, these data are coded using schemas called Rich Snippets in different formats - JSON-LD, Microdata, RDF-a Using these formats the search engine bots and other applications identifies the information and present to the users according to their search and needs.
Example: SERP results about any particular person bio, company information, Movie data, actors data, recipes