How does search work? How do search engines find what you are looking for? The world's most used search engine, Google, answers that question. Google has recently created a website that explains how they do searches.
But don't get your hopes up too high. Companies that specialize in search engines are not about to open up their algorithms or tell us how they rank sites. Those are closely held secrets. Google does, however, show us how they do some of their search strategies and how they stay ahead of other search engines.
Google's site on how they search
Take a look at the site. It is quite interesting. And when you are done you will better understand how they can do so many searches so quickly.
via Examiner National Edition Gadgets & Tech Channel Articles http://www.examiner.com/article/how-does-search-work-google-answers?cid=roadrunner