The web as it currently exists would not be possible without search engines. They are an integral part of the Web and can also be seen as a part of the Web's infrastructure. Google alone now serves over two trillion search queries per year.11 While there seems to be a multitude of search engines on the market, there are only a few relevant search engines in terms of them having their own index (the database of Web pages underlying a search engine). Other search engines pull results from one of these search engines (for example, Yahoo pulls results from Bing), and should therefore not be considered search engines in the true sense of the word. Globally, the major search engines with their own indexes are Google, Bing, Yandex, and Baidu. Other independent search engines may have their own indexes, but not to the extent that their size makes them competitive in the global search engine market.
While the search engine market in the U.S. is split between Google and Bing (and its partner Yahoo) with approximately two-thirds to one-third, respectively,10 in most European countries, Google accounts for more than 90% of the market share. As this situation has been stable over at least the last 10 years, there have been discussions about how much power Google has over what users get to see from the Web, as well as about anticompetitive business practices, most notably in the context of the European Commission's competitive investigation into the search giant.3