What is Microdata Schema?

Schema.org gives an accumulation of shared vocabularies website admins can use to increase their pages in ways that can be comprehended by the real web indexes: Google, Microsoft, Yandex and Yahoo! You utilize the schema.org vocabulary alongside the Microdata, RDFa, or JSON-LD arrangements to add data to your Web content.

Schema.org is the result of collaboration between Google, Bing, Yandex, and Yahoo! to help you provide the information their search engines need to understand your content and provide the best search results possible at this time.

Schema markup is code (semantic vocabulary) that you put on your website to help the search engines return more informative results for users. If you've ever used rich snippets, you'll understand exactly what schema markup is all about

Microdata is a WHATWG HTML specification used to nest metadata within existing content on  web pages. You use the schema.org vocabulary along with the Microdata formats to add information to your web content.