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.
Hidden Web: This is another name favored by some for the Invisible Web.
Horizontal Search: This term is used to describe the kind of searching done when using a general-purpose search engine which draws on a broad number of surface Web resources.
Mining: This term is often used to describe the process of finding Information on the Web.
Niche Search: Niche searching refers to a very specific, narrow, but deep search into specialized resources from both the surface and Invisible Web. Niche is even more specialized than a vertical search (See definition below).
Opaque Web: This term refers to material that can be but is not included in search engine results. Some omissions may be due to new material being added and not yet picked up by web crawler programs or information being placed deeper within a site than web crawlers usually reach.
Private Web: These sites have been intentionally excluded from web search engine results by their sponsors. They may have password protections or be programmed as a "Noindex" site, which tells web crawlers not to index the page.
Proprietary Web: This term refers to sites that require the user to be registered for use before access can be given.
Search Engine: This refers to a computer program that can help users find information on the World Wide Web.
Spider: Also referred to as a "Web Crawler," this program used by search engines, retrieves information from a web page and follows and web links for indexing purposes.
Static: Fixed and reliable links are referred to as "static."
Subscription Databases: These databases are fee based.
Surface Web: Sometimes referred to as the "Visible Web", it represents World Wide Web content found by using search engines.
Vertical Search: This term is used to describe searching which delves deeply into a subject. It implies the researcher is using specialized search tools and retrieving materials from both the surface and Invisible Web.
Visible Web: See "Surface Web."
Web Crawler: Sometimes called a "spider," this is a program used by search engines to locate and retrieve web pages and the references linked to them for indexing purposes.
Updated Jan. 2009