Google introduced the Hummingbird algorithm in 2013 to improve search results. Hummingbird analyzes longer, more complex questions to provide more direct answers compared to previous algorithms like Panda and Penguin. It uses information like user location and interests to personalize results. The algorithm also leverages Google's Knowledge Graph to understand context and relationships to better answer follow-up questions. Hummingbird aims to have a more human-like conversation with users through its semantic search capabilities.