Google Dataset uses Schemas, a set of "types" associated with a set of properties to describe the dataset. More and more repositories use schema.org and similar standards to describe their datasets,
"Schema.org is a collaborative, community activity with a mission to create, maintain, and promote schemas for structured data on the Internet. In addition to people from the founding companies (Google, Microsoft, Yahoo and Yandex), there is substantial participation by the larger Web community, ... Since April 2015, the W3C Schema.org Community Group is the main forum for schema collaboration, and provides the public-schemaorg@w3.org mailing list for discussions. Schema.org issues are tracked on GitHub." <https://schema.org/docs/about.html>
Organization of Schemas - "The schemas are a set of 'types', each associated with a set of properties. The types are arranged in a hierarchy. The vocabulary currently consists of 797 Types, 1457 Properties 14 Datatypes, 86 Enumerations and 462 Enumeration members." <https://schema.org/docs/schemas.html>
TIPS: You can use the tool they provide to validate your structured data - https://validator.schema.org/
