Google recently unveiled a new resource that interactively shows how a Google search works and its various dependencies. You can find it on ‘How Search Works: The Story’. The web page itself is quite nifty with a behaviour of a dynamic infographic. Basically as you scroll down the page you will unfold the Google Search Story: Crawling and Indexing, Algorithms and Fighting spam. So take a scroll down on that page and educate your self a bit further on this complex process that gives us simple results in a fraction of a second.
http://www.google.com/insidesearch/howsearchworks/thestory/
One good point is that this “dynamic info-graphic” has a better coverage on automatic spam filtering.