Honestly its not. There is a paper in SIGIR 2019 about how it was trained and works called 'Generic Intent Representation in Web Search'. The jist of it is if a

Honestly its not. There is a paper in SIGIR 2019 about how it was trained and works called 'Generic Intent Representation in Web Search'. The jist of it is if a document has a sat click from multiple queiries make those vectors closer together. Do this over a few billion urls and documents and you can make a vector represenation for any query.