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Deep Web: Important Definitions

The Deep Web Library Guide discusses why the Deep Web exists and what it contains. The Guide also provides tools for searching the Deep Web, along with resources for further information.

Defining the Deep Web

The Deep Web consists of all information on the World Wide Web which cannot be located by general-purpose search engines (Google, Yahoo, Bing etc.).  There's a large amount of information which even powerful engines such as these cannot find.  To understand why, click on The Database Challenges and Other Challenges tabs in this guide.

Sometimes you'll hear the term "Dark Web." The Deep Web and the Dark Web are not the same thing, as this helpful article from BrightPlanet explains: Clearing up Confusion: Deep Web vs. Dark Web

Web Page vs. Web Site

A web page is often defined as a document on the World Wide Web with a single, unique web address.  A web site is a group of web pages created by an individual, group or organization.  Pages within a web site link to one another and are usually related by topic.  One web site may contain many web pages.

Example: Saint Louis Community College has a web site.  The opening page of the web site is

Within this site are numerous individual web pages, such as the STLCC Student Resources Page:

When reading about the Deep Web in this guide, keep the distinction between web page and web site in mind.

Other Important Terms

Synonyms for Deep Web:

  • Hidden Web
  • Invisible Web
  • Secret Web

      Synonyms for Web Crawler:

        • (Web) Spider
        • (Web) Bot

        Open Web, Visible Web, Surface Web: The portion of the Web which is accessible to general search engines.  This part of the Web is free of charge, available for use by anyone. However, note that there are free sites within the Deep Web as well, which for one reason or another are inaccessible to web crawlers.

        St. Louis Community College Libraries

        Florissant Valley Campus Library
        3400 Pershall Rd.
        Ferguson, MO 63135-1408
        Phone: 314-513-4514

        Forest Park Campus Library
        5600 Oakland
        St. Louis, MO 63110-1316
        Phone: 314-644-9210

        Meramec Campus Library
        11333 Big Bend Road
        St. Louis, MO 63122-5720
        Phone: 314-984-7797

        Wildwood Campus Library
        2645 Generations Drive
        Wildwood, MO 63040-1168
        Phone: 636-422-2000