The invisible web (also known as the deep web) is the name given to the large amount of pages on the World Wide Web that are not indexed, and unable to be indexed, by search engines. The invisible web mainly consists of dynamically generated pages that are founded on databases and respond to queries. In a 2000 study by the search company BrightPlanet, the inaccessible part of the web was estimated to be about 500 times larger than what search engines already provide access to.
