Query understanding is the process of inferring the intent of a search engine user by extracting semantic meaning from the searcher’s keywords.[1] Query understanding methods generally take place before the search engine retrieves and ranks results. It is related to natural language processing but specifically focused on the understanding of search queries. Query understanding is at the heart of technologies like Amazon Alexa,[2] Apple's Siri.[3] Google Assistant,[4] IBM's Watson,[5] and Microsoft's Cortana.[6]