I just watched a youtube video on how does google search actually works, I knew many things that were shown in the video before, but for some of things I was not sure about, I got my answers after watching the video.
About Google.com ?
As a company, Google focuses on three key areas: Search, Ads and Apps. Search is our core technology; ads are our central business proposition; and apps are the umbrella over our web-based software that you can access anywhere, any time. While each of these has a lot of technology under the hood, the basic tenets for Search, Ads and Apps are very simple. We’ve created some short videos explaining the principles behind our core services.
Go to http://www.google.com/howgoogleworks/ to know and understand how does three main things focused by google works.