Google, being the most widely used search engine, requires special consideration in optimizing your website for search engines. Google has expanded its services from being a simple search engine to offer google email, google docs, google adsense, google adwords, android operating system, google analytics, google webmaster tools, and several others.

The page offers search engine dependency of various prominent search engines. Though the article is a bit older, the search engines are still inter related to one another one way other other. Prominent search engines includes Google, Bing, Yahoo, Ask, duckduckgo, and others.