The Deep Web (also called the Deepnet, the Invisible Web, the Undernet or the hidden Web) refers to World Wide Web content that is not part of the Surface Web, which is indexable by standard search engines.

It should not be confused with the dark Internet, the computers that can no longer be reached via Internet, or with the distributed filesharing network Darknet, which could be classified as a smaller part of the Deep Web.

Mike Bergman, founder of BrightPlanet, credited with coining the phrase, has said that searching on the Internet today can be compared to dragging a net across the surface of the ocean: a great deal may be caught in the net, but there is a wealth of information that is deep and therefore missed. Most of the Web's information is buried far down on dynamically generated sites, and standard search engines do not find it. Traditional search engines cannot "see" or retrieve content in the deep Web—those pages do not exist until they are created dynamically as the result of a specific search. The deep Web is several orders of magnitude larger than the surface Web.

Harvey Mackay (born 1932 in Saint Paul, Minnesota) is a businessman and columnist. Mackay is perhaps best known as the author of five business bestsellers, including Swim With the Sharks (Without Being Eaten Alive), Beware the Naked Man Who Offers You His Shirt and Dig Your Well Before You're Thirsty. He is a nationally syndicated columnist, and one of America's most popular business speakers. He is also founder, Chairman and CEO of Mackay Envelope Corporation, whose story he tells in anecdotes sprinkled throughout his books.

Harvey Mackay is the author of the #1 New York Times bestsellers Swim with the Sharks Without Being Eaten Alive and Beware the Naked Man Who Offers You His Shirt; both books are among the top 15 inspirational business books of all time, according to the New York Times.^{[citation needed]} His books have sold more than ten million copies worldwide. His newest book Use Your Head To Get Your Foot In The Door: Job Search Secrets No One Else Will Tell You, was released on February 18, 2010. When Larry King interviewed Harvey in late February 2010, Larry said, "I really believe this is the most important book right now." The book is already in its fourth printing as of March 1, 2010. It immediately climbed the bestseller list at Amazon.com and hit #1 in four categories: Job Hunting, Counseling, Vocational Guidance and Education. It can also be found on the Wall Street Journal Business Bestseller list.