The Major Meta Search Engines Metacrawlers provide an easy way to find combined listings from a number of different crawler-based search services, and sometimes this can assure more adequate results.
The Major Web Directories and Portals These directories consist of huge database of web sites links organized in categories by human editors, and provide the second way to find relevant information.
Popular Web Directories In contrast to search engines, which use crawlers or robots to collect web site content, web directories are organized by editor, which means more relevant search results.