Google's BERT (Bidirectional Encoder Representations from Transformers) is a natural language processing model designed to understand the context of words in search queries. It analyzes the relationships between words in a sentence, allowing it to grasp the meaning behind user searches more effectively. BERT improves the accuracy of search results by considering the full context of a query rather than just individual keywords. This helps Google provide more relevant answers, especially for complex questions and conversational language, enhancing the overall user experience in Google Search.