Topics are specific search areas that Google is developing with the help of expert contributors. Contributors to topics annotate websites that they think are especially useful, relevant, or authoritative to a topic with pre-defined category labels. These labels appear as links at the top of search results pages when users search for something related to the topic. Users can click these labels to refine their search results, giving priority to sites that have been labeled by topic contributors.
You can sign up to contribute to any of the current topics.
