Yahoo! Search is a web search engine, owned by Yahoo!, Inc. and is currently the second largest search engine on the web, after its competitor Google.
Originally Yahoo! Search started as a web directory of other websites, organized in a hierarchy, as opposed to a searchable index of pages. In late 1990s, Yahoo! evolved into a full-fledged portal, with eventually a search interface.
Yahoo! Search, originally referred to as Yahoo! provided Search interface, would send queries to a searchable index of pages supplemented with its directory of sites. The results were presented to the user under the Yahoo! brand. Originally, none of the actual web crawling and storage/retrieval of data was done by Yahoo! itself. In 2001 the searchable index was powered by Inktomi and later was powered by Google until 2004, when Yahoo! Search became independent. Yahoo! Search major competitors are: Google Search, Live Search and Ask Search.
The team at Yahoo! Search frequently blogs about search announcements, features, updates and enhancements. The Yahoo! Search Blog, as stated provides A look inside the world of search from the people at Yahoo!. This includes index updates named Weather Updates and their Yahoo! Search Assist feature.