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. It's the internet that Google doesn't show us; some of it dull, some of it private, some of it deliberately hidden.
Mining the Deep Web. Google indexes 4 billion pages, but there are hundreds of billions of documents out there in the Deep Web that are effectively unreachable by search engines because they are locked in databases or are unsearchable media. It looks like Yahoo is going to start giving us a peek by providing unified access to a wide variety of sites that are ordinarily only searchable by their own custom search engines.
posted by badstone
on Mar 2, 2004 -