Wikidata is a structured knowledge base.
Unlike Wikipedia, Wikidata stores information in a structured format. Each item has a unique identifier that starts with "Q", and all data is mostly added in the form of statements. For example, the fact that Wellington is the capital of New Zealand is stored as Q664 > P36 > Q23661. Wikidata statements can be illustrated as follows:
The data stored in Wikidata is used by Wikipedia.
The entire Wikidata content can be downloaded in the JSON format. The database dumps are regularly published at https://dumps.wikimedia.org/wikidatawiki/entities/.