“I am using Google to search the Internet.”

Technical speaking, this statement is slightly incorrect because, according to Matt Cutts, when you do a search on Google, you aren’t searching the World Wide Web, you’re only searching Google’s index of the web which may not have every single website or web page that’s out there on the Internet.

Jargon aside, if you ever want to explain someone how Google indexes billions of web pages and how it can fetch the right results for your search query in seconds, just show them this page.