Schema Types

Schema.org – Structured website metadata for search engines. Helps create Rich Snippets (google.com widgets).

• JSON-LD – Metadata using JSON. Google’s prefered markup. ((https://jsonld.com/google-loves-json-ld-seo/))
• Microdata – Part of the HTML Standard
• RDFa – W3C Recommendation for adding metadata to HTML and other XML based documents
• OpenGraph – Metadata for social media (twitter and facebook, etc..)