Yahoo search engine was the king of all the search engines a few years ago. It is a product which came from California. Yahoo mainly focuses on the collection of personal data to satisfy more and give satisfactory results. It is not only a former king but also a current competitor. It provides a piece of decent information which attracts more people and starts expansion too.
Then the Microsoft company made a deal with Yahoo and merged with bingo then acted as Microsoft search alliance. The fundamental drawback of the Yahoo search engine is, unable to keep the personal information confidential. This helped Google to rise and occupy the market share.