bluesyemre

• The internet is an iceberg. And, as you might guess, most of us only reckon with the tip. While the pages and media found via simple searches may seem unendingly huge at times, what is submerged and largely unseen – often referred to as the invisible web or deep web – is in fact far, far bigger. What we access every day through popular search engines like Google, Yahoo or Bing is referred to as the Surface Web. These familiar search engines crawl through tens of trillions of pages of available content (Google alone is said to have indexed more than 30 trillion web pages) and bring that content to us on demand. As big as this trove of information is, however, this represents only the tip of the iceberg. Eric Schmidt, the CEO of Google, was asked to estimate the size of the World Wide Web. He estimated that of roughly 5 million terabytes of data, Google has indexed roughly 200 terabytes, or only .004% of the total internet.

http://www.onlineuniversities.com/articles/students/how-to-search-invisible-web/