Calm.com. T.y.p.o.r.g.a.n.i.s.m : ASCII-O-Matic. What can you learn on youtube? - Tomash.soup. Invisible Web: What it is, Why it exists, How to find it, and Its inherent ambiguity. What is the "Invisible Web", a.k.a. the "Deep Web"?
The "visible web" is what you can find using general web search engines. It's also what you see in almost all subject directories. The "invisible web" is what you cannot find using these types of tools. The first version of this web page was written in 2000, when this topic was new and baffling to many web searchers. Since then, search engines' crawlers and indexing programs have overcome many of the technical barriers that made it impossible for them to find "invisible" web pages.