The following infographic of how a Google search works (courtesy of the big “G” itself) breaks down the information into its most basic form, illustrating the individual steps of the search process, from before you click the search button, to calculating the exact rankings, to ultimately serving the appropriate results.

How Google Searches Work - Infographic

Should you wish to discuss this process, and what we can do to increase your search visibility, please visit my SEO page or get in touch to discuss your requirements.

Original source (PDF): http://www.google.com/insidesearch/howsearchworks/crawling-indexing.html