When people talk about search engines, they’re typically referring to Google, Bing and Yahoo (Yahoo search is powered by Microsoft). According to one study, these “Big Three” represent over 95% of all online searches in the U.S.  There are many other major search engines in other countries, like Baidu in China, but the collective amount of searches they produce in the U.S. is insignificant.

The king of search is obviously Google. What made Google so popular is that it revolutionized the search engine industry by using link popularity to measure relevance of content. The method proved to be so effective that Google became a household word. Because studies have shown that roughly two-thirds of all searches are conducted on Google, we will focus on it primarily to define your basic SEO strategy.

How Does Google Work?

According to Google, the web today is made up of billions of websites consisting of over 60 trillion individual web pages, and that number is growing every day. Google (and other search engines) work by crawling the Web, following links from page to page. Site owners can tell Google what to crawl, but Google also does a fine job on its own.

Google then sorts the pages based on their content (and hundreds of other factors), and maintains this data in what’s called “the index.” The index is Google’s massive database of all metadata on the Web.

As you search for something, Google uses a number of programs and formulas (algorithms) to determine what you are trying to find (spelling, auto complete, synonyms, and much more). Based on these clues, Google pulls the relevant web pages from the index. Then Google ranks the results using more than 200 factors (such as content quality and freshness) to provide you the best possible matching results.