Intro: These three terms are often a source of confusion, especially in connection with cybercrime and where that comes from. If you think that search engines like Google know about everything on the internet, you'd be wrong. Some stats from Worldwidewebsize.com show at the start of November 2017, search engines have indexed at around 4.5 billion pages, which is a lot, but you'd be surprised to know that in reality it's only 10 percent of the whole web.