Database: A system of data organized in records and fields for fast
retrieval. Databases have their own individual search tool.
Deep Web: This is another name favored by some for the Invisible
Web.
Directory: This kind of search tool categorizes information
sources. It does lead the user to the front door of sites that offer information. Directories are by their nature selective rather than exhaustive and can be limited in scope.
Dynamic (dynamically generated): This refers to information
generated only in response to a specific database query. It ceases to exist afterwards.
Harvesting: This term is often used to describe the process of finding information on the Web.