Organized, categorized listings of Web sites.
The terms “Web directory” and “search engine” are often used interchangeably. Web directories are organized Web site listings put together by human reviewers, whereas search engine listings are put together by automated systems and lack a navigable structure. Much of the confusion stems from the various hybrid models that have developed over time, as search engines have incorporated directory features to assist with issues such as categorization and site quality.
There are advantages and drawbacks to using a Web directory as opposed to a search engine. One vehicle may be better suited to certain types of searches than the other. Directories place an emphasis on linking to site home pages and try to minimize deep linking. This makes directories more useful for finding sites instead of individual pages. Some directories attempt to solve this shortcoming by partnering with a search engine for supplemental listings.
Web site directory
The Directory Listing Advantage
ClickZ (August 9, 2000)