Many websites have content in multiple languages targeting multiple countries. For the purposes of SEO, it is important to explicitly specify the target region and language codes for each page and link different page versions to each other.
Normally, each page only includes content in one primary language and targets a specific country or region.
The Google Knowledge Graph is a knowledge base owned by Google and used in various products in services such as Search and Maps. It includes the definitions and facts about movies, books, TV shows, celebrities, authors, locations, companies, medical conditions, and many other types of entities, all available in multiple languages.
A working example of Article structured data...