AltaVista , for example, now features Categories in partnership with the LookSmart directory. The following categories of Web search engines are presented to help compare search engines with similar basic design and features. Follow each of the links for a more in-depth description of that category of search engine. A Web directory is a human-selected databases of Web sites organized into subject categories and subcategories. Directory services use selection criteria for choosing links to include, though the selectivity varies among services.
Most directories offer a search engine mechanism to query the service.
Yahoo , LookSmart , Lycos and Librarians' Index to the Internet are examples of Web directories. Web directories may review sites or list the sites with the best content at the top of the list. While Web directories are smaller than the large Web indexes they can help you quickly find targeted information on general topics. Academic and professional directories are created by librarians or subject experts and tend to be associated with libraries and academic institutions. These collections are created in order to enhance the research process and help users find high quality sites of interest.