You can divide net search services in three; Search engines, Meta search engines and Directory search. In today's jungle of net search resources, the best one is called Google. Google represents approximately 35% of all net searches. Google also delivers net search results to other search engines. If you include those, the total number is much higher.
Search engines (Crawlers) are automated services that find websites by themselves and make a copy of it for their database. The results are ranked by different criteria's depending on which net search engine you use. Some search engines are free (E.g. Gigablast), while others charge you for top placements (E.g. Ask Jeeves).
Meta search engines do not deliver own results. They conduct own net search queries in different search engines and directories before the results are presented.
Directory search is search in data bases where people decide which sites should be included. In some directories you can submit your site cost free (E.g. Open Directory), while other charge you (E.g. Kvasir). In directories you can find what you seek by browsing the directory or conduct a net search of the content in the directory.
