an alphabetical list of words relating to a specific subject, text, or dialect.
Use of a pre-defined data sharing format to provide information to search engines in a structured, contextual manner. A popular pre-determined schema is available on schema.org. Such data structures are embedded in the HTML pages. Contains a method of declaring an object (blog post) and a set of related fields and values (title, description, author, publish data).
Popular for many common data fields like hotel reviews, blog posts. Increasingly used to power rich results and knowledge graph cards. Microdata powered pages have better visibility on Google search results. 3 important markup formats are JSON-LD, Microdata, Microformat and RDF.
When you provide structured data markup for your online content, you make that content eligible to appear in more than one category of Google Search – natural results, maps, answer box, news.