What is "schema"
Schema.org is a collaborative community activity with the mission of creating, maintaining and promoting schemes for structured data on the Internet, on web pages, in email messages and beyond.
The Schema.org vocabulary can be used with many different encodings, including Rdfa, Microdata and JSON-LD. These vocabularies cover entities, relationships between entities and actions and can be easily extended through a well-documented extension model. More than 10 million websites use Schema.org to mark their web pages and email messages. Many apps from Google, Microsoft, Pinterest, Yandex and others already use these vocabularies to provide rich and extensible experiences.
Founded by Google, Microsoft, Yahoo and Yandex, the vocabularies Schema.org are developed by an open community process , using the [email protected] mailing list and through Github .
A shared vocabulary makes it easy for webmasters and developers to decide on a scheme and get the maximum benefit for their efforts. It is in this spirit that the founders, together with the larger community, come together - to provide a shared collection of schemes.